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Vision

Potential

Deployment Roadmap

Strategic Research Agenda

Solar Heating and Cooling or a

Sustainable Energy Future in Europe

R e v i s e d V e r s

i o n



Image on Title: The Sun

(Source: Triolog, Freiburg, Germany)



This document was prepared by the European Solar Thermal Technology Platorm

(ESTTP).

Reproduction is authorised provided the source is acknowledged.

The Secretariat o the ESTTP, which was responsible or the fnal editing, layout and

printing o this document, is supported by the Sixth EU Framework Programme orResearch and Technological Development, FP6 (Contract Number TREN/07/FP6EN/

S07.68874/038604).

The sole responsibility or the content o this publication lies with the authors. It does

not represent the opinion o the European Communities. The European Commission is

not responsible or any use that may be made o the inormation contained therein.

The ESTTP Secretariat is jointly run by:

European Solar Thermal Industry Federation (ESTIF)•

European Renewable Energy Centres Agency (EUREC Agency)•

PSE AG•

Contact:

ESTTP

c/o ESTIF

Renewable Energy House

Rue d‘Arlon 63-67

B-1040 Brussels

BelgiumTel.: +32 2 546 19 38

Fax: +32 2 546 19 39

E-Mail: [email protected]

Web: www.esttp.org

Imprint

Solar Heating and Cooling

or a Sustainable Energy Future in Europe



1 FOREWORD 4

2 EXECUTIVE SUMMARY 5

3 ABOUT THE EUROPEAN SOLAR THERMAL TECHNOLOGY PLATFORM 9

4 THE UNIQUE BENEFITS OF SOLAR THERMAL 13

5 A TECHNOLOGICAL PERSPECTIVE ON SOLAR THERMAL POTENTIAL 175.1 Current trends in the ST market 185.2 Short-medium term ST potential 21

5.3 Main applications in short-medium term 21

5.4 Medium-long term ST potential (advanced technologies) 22

6 VISION 2030 256.1 Macro-economic benefts 26

6.2 Cost competitiveness 27

6.3 Employment 31

6.4 International competition and technological leadership 34

7 DEPLOYMENT ROADMAP 377.1 Towards the active solar building 38

7.2 Industrial process heat, including water treatment and desalination 46

7.3 District heating and cooling 57

Table o Contents





8 STRATEGIC RESEARCH AGENDA 65

8.1 Solar thermal collectors 668.1.1 Low tempera ture collectors 67

8.1.1.1 Technology status 67

8.1.1.2 Potential and challenges or technological development 68

8.1.2 Process heat (medium temperature) collectors 708.1.2.1 Technology status 70

8.1.2.2 Potential and challenges or technological development 71

8.1.2.3 Non-technical challenges or solar process heat collectors 71

8.1.3 R&D agenda 72

8.1.4 Timetable 74

8.2 Thermal storage 768.2.1 Technology status 77

8.2.2 Potential and challenges or technological development 79

8.2.3 Research agenda 79

8.2.4 Timetable 82

8.3 Solar thermally driven cooling and refrigeration 838.3.1 Technology status 868.3.2 Challenges and potential or technological development 87

8.3.3 R&D needed to achieve the goals 88

8.3.4 Timetable 91

8.4 Multi-functional components 948.4.1 Technology status 948.4.2 Challenges and potential or technological development 96

8.4.3 Research agenda 96

8.4.4 Timetable 988.5 Control systems 1008.5.1 Technology status 101

8.5.2 Challenges and potent ial or technological development 1018.5.3 Timetable 104

8.6 Water treatment (desalination) 1058.6.1 Technology status 106

8.6.2 Barriers to increased deployment 107

8.6.3 R&D needed to achieve the goals 108

8.6.4 Timetable 109

9 RESEARCH INFRASTRUCTURE 113

9.1 Solar assisted cooling and air-condit ioning 114

9.2 Process heat collectors 116

9.3 Heat storage 116

10 REFERENCES 119



Dear Reader,

For a long time, low-temperature solar thermal has only played a minor role compared to other renewable energy sources. The popular concep- tion concerning energy was ocused almost exclusively upon electricity generation, even though heating constitutes almost 50% o the total energy consumption. Solar thermal was considered mainly to provide or water heating needs, where technologically mature solutions exist. Inthe scenarios o uture energy strategies, heat generation consequently played only a very small role.

The situation has changed dramatically. Without a doubt, the Europeangoal o covering 20% o energy needs with renewable energy can only

be reached with a signifcant increase o renewable energy capacities in the heating sector. The explosion o crude oil and natural gas prices along with increasing import dependency have urther increased public attention and interest. However, the question remained which role solar heating was supposed to play.

At the same time, it is nothing new that low-temperature solar thermal technology has the greatest potential among all renewable energies inthe heating area. Today, it are primarily the advancements made by the European Solar Technology Platorm (ESTTP) that outline the large technological development potential o low-temperature solar thermal. This potential is triggered by the enhancements to system types and components but also primarily in the development o new uses or the technology, such as solar heating, process-heating generation, district heating and solar assisted cooling.

Already in 2006, the ESTTP ormulated its 2030 vision or low-temperature solar thermal. Since then, numerous experts rom the industry and research sectors o Europe have worked on a strategic research agenda to implement this vision. With this document, you hold the results o this work in your hands. It is the frst time that the technological perspectives o low-temperature solar thermal have been so systematically presented.It will certainly contribute to evaluate the opportunities or solar thermal more realistically.

Out o this research program comes the challenge o overcoming the research unding defcits o the previous years. Low-temperature solar thermal must play an important role in the research programs o the EU and the member states. The unding or solar thermal research must be signifcantly increased and the research capacities must be systemati-

cally expanded.

I would like to thank all o the experts who have been involved in this extensive task and cordially invite all who are interested to use this document to obtain a comprehensive overview o the technological perspectives on low-temperature solar thermal and work together with us to implement this research strategy. On this note, I wish you a most interesting read.

Sunny regards,

Gerhard Stryi-Hipp

The paper has been written by the European Solar Thermal Technology Platorm(ESTTP). The ESTTP was co-ounded and is supported by the European Solar Thermal

Industry Federation (ESTIF) and the by EUREC Agency, an association representing the

European research institutes active in the renewable energy feld.

4

Foreword1





Solar thermal energy is an extremely convenient source o heating; and a technology

that does not rely on scarce, fnite energy resources. It has the potential to cover 50%

o the total heat demand. To reach this goal existing technologies have to expand and

new technologies should be developed or new sectors like apartment buildings and

the industrial sector. Research is needed or new applications like, compact seasonal

storage, industrial applications (up to 250 °C) and solar cooling.

In this document the current trends and technological perspective is described and

the vision or 2030. Then the deployment road map is given to reach this perspective.

The strategic research agenda and the research inrastructure needed or reaching the

goals are described in the chapter 8 and 9.

This vision, deployment road map and research agenda was developed by the Euro-

pean Solar Thermal Technology Platorm (ESTTP). The ESTTP was set-up by the Euro-

pean Solar Thermal Industry Federation (ESTIF) and the European Renewable Energy

Research Centres Agency (EUREC Agency). In the plat orm about 100 leading experts

in the feld o solar thermal research and applications co-operated to write this report.

The main fndings o this report are:

Current status

The demand or heating and cooling is 49% o the total energy demand in Eu-•

rope, most o which is needed at low- to medium temperatures (up to 250°C).

Technologies are available or can be developed to cover in principle most o this•

demand.Solar thermal applications do not depend on fnite sources and solar energy is•

available everywhere.

Already today, solar thermal energy or domestic hot water preparation and or•

space heating is a developed technology with a high penetration rates in some

countries.

Vision 2030

Solar thermal can cover 50% o the total heat demand, i the heat demand is frst•

reduced by energy saving measures.

To reach this goal new applications have to be developed and deployed. The•

main ones are the active solar building, the active solar renovation, industrial ap-

plications up to 250 °C, solar heat or district heating and cooling.

5

Executive summary2



Figure 1 shows how this long term goal o the vision can be reached and how this

is split over current technologies (business as usual), advanced market deployment

(by developing new technologies and application sectors) and new applications

where R&D is needed to develop them (like compact heat storage and high tempera-

ture collectors)

Figure 2 shows how this target o 50% compares to the total heat demand. First the

energy demand can be reduced by 40% and rom this reduced demand solar cancontribute 50% in the long run (around 2050). The division over the application sec-

tor is included.

6

Figure 1: Growth in solar thermal energy use in dierent scenarios. (Source: ESTIF, 2008)

Figure 2: Contribution o solar thermal to EU heat demand by sector, assuming that the total heat demand can

be reduced by energy conservation and a 40% increase in efciency by 2030. (Source: AEE INTEC, 2008)

2 Executive summary



Deployment roadmap

The deployment roadmap shows what research, development and demonstrations are

needed to develop the main application felds: residential & commercial buildings,

industrial process heat, desalination and water treatment and district heating. Beside

the technological developments also the market issues are described.

The strategic research agenda

To reach the goal o supplying 50% o the heat demand, a new generation o solarthermal technologies need to be developed or new application areas. The main

new applications are: solar combi-systems using compact seasonal storage, higher

temperature collectors or industrial applications and solar cooling. The main research

challenges are:

To develop compact long-term efcient heat storage. The storage technology•

should make it possible to store heat rom the summer or use in winter in a cost-

eective manner

To develop new materials or solar systems. The new materials are needed be-•

cause the materials as currently applied have a limited technical perormance and

could potentially be replaced with cheaper options.

Basic research or improvement in solar cooling, high temperature solar collectors•

and solar desalination.

For each application feld the industrial development and the basic research that isneeded is described in detail.

The research infrastructure

The Research Inrastructure needed to implement the Research Agenda is a s tructured

collaboration o research institutes and industry.

It includes:

a RD&D Network;•

a Joint European Laboratory dedicated to solar cooling and process heat; and•

Regional Solar Cooling and Process Heat Development Centres or demonstration,•

technology transer and training.

Future actions

To reach the goals, a whole range o activities is needed rom basic research to promo-

tion, because solar thermal is a technology that includes applications that are cost-

eective (like solar water heaters in sunny climates) to completely new technologies

(like compact chemical heat storage). The development o the current markets is thebasis. With these existing technologies new application areas, like industrial heat and

multi-amily houses can be developed. Improved technologies can urther open these

markets and expand them to solar cooling, solar desalination and higher temperature

applications. Basic research should lead to a new generation o solar technologies likeseasonal storage o solar heat and a new generation o solar systems with improvedprice perormance.

7



The Earth seen from Apollo 17

Source: http://de.wikipedia.org/wiki/Bild:The_Earth_seen_rom_Apollo_17.jpg

(Author: Image courtesy o Earth Sciences and Image Analysis Laboratory,NASA Johnson Space Center. File Name AS17-148-22727;

created by NASA)

8





9



A Strategic Research Agenda

About the European Solar Thermal

Technology Platorm

3



This document has been produced by the European Solar Thermal technology Platorm

(ESTTP).

Technology Platorms are seen as a very important tool to rame and promote the u-

ture development o a technology. In order to strengthen the pan-European understand-

ing and development o solar thermal technology an Initiator Group has been workingtowards a ESTTP since the beginning o 2005.

Several active members o the European Solar Thermal Industry Federation (ESTIF)

and the European Renewable Energy Centres Agency (EUREC Agency) ounded the

ESTTP Initiator Group. Both organisations strongly support the plat orm. Furthermore itinvolves “neighbouring” industries (or example, rom construction, heating ventilation

and air conditioning and metals sectors) as well as policy makers.

The diagram below shows the structure of the Technology Platform.

High level Group: Consists o CEOs and representatives rom the European Com-

mission and national ministries. It provides direction and advice on the work o the

Technology Platorm.

Steering Committee: Is responsible or managing the Technology Platorm.

Focus Groups: Coordinate the activities o one feld o research and provide inorma-

tion or a wide number o members interested in a par ticular feld o solar thermal re-

search such as the building sector, industrial applications or market and policy issues.

The Focus Groups are subdivided into 12 working groups.

Steering Committee

Chair: Gerhard Stryi-Hipp,

Werner Weiss, Nigel Cotton

Today: 17 members

Focus Group 1

Solar thermal sys-

tems for buildings

(heating and cooling)

Chair: Volker Wittwer

+ Working Groups

Focus Group 2

ST systems for

industrial applications

(including refrigera-

tion)

Chair: Werner Weiss

+ Working Groups

Focus Group 3

ST deployment,

strategy and scena-

rios (market and

policy)

Chair: Teun Bokhoven

+ Working Groups

National

Technology

Platforms

ESTTP Support Group

More than 170 members

ESTTP Secretariat

ESTIF / EUREC / PSE

High Level GroupStructureof the ESTTP

Figure 3: Current structure o the European Solar Thermal Technology Platorm

3 About the European Solar Thermal Technology Platorm

3 About the European Solar Thermal Technology Platorm

10



Working Groups: Work on dierent issues, such as undamental research, applied re-

search, market deployment and political instruments. These groups take responsibility

or progressing the work at a detailed level. All interested European experts can apply

or membership.

National Mirror Groups: Work on a national level to provide input or the ESTTP andharmonise the European and national research agendas. National mirror groups will

be initiated by national experts.

Support Group: More than 180 companies, R&D institutes and associations have

become Support Group members. The Support Group comprises all companies andorganisations that have signed the let ter o support or the ESTTP. They are invited to

participate in the ESTTP working groups and to attend General Assemblies.

Structure o Focus and Working Groups

Focus Group 2

Solar Heat for Industrial Applications

Chair: Werner Weiss, AT

WG 2 A

Process Heat

C. Brunner,

AT

WG 2 B

Water Treat-

ment

H. Müller-Holst,

DE

WG 2 D

PH Collectors

MT Storage

A. Häberle, DE

R. Tamme, DE

WG 2 E

District Heating

J.O. Dalenbäck,

SE

WG 2 C

Refrigeration

D. Mugnier, FR

M. Motta, IT

Focus Group 3

Market deployment, strategy and scenario development

Chair: Teun Bokhoven, NL

WG 3 A

Market assessment

& incentive schemes

L. Bosselaar, NL

WG 3 B

The solar thermal roadmap

R. Buchinger, AT

Focus Group 1

Solar Thermal Systems for Buildings

Chair: Volker Wittwer, DE

WG 1 A

Collectors

M. CollaresPereira, PT

WG 1 B

Storage of

Thermal Energy

W. van Helden,NL

WG 1 D

Active Solar

Renovation

R. Schild, DEI. Opstelten, NL

WG 1 E

System Design

and Perfor-

manceH. Drück, DE

WG 1 C

Buildings with

High Solar

FractionW. Sparber, IT

Figure 4: Structure o Focus and Working Groups 1



11



12

Diameter comparison of Sun and Earth

Source: http: //de.wikipedia.org/wiki/Bild:Sun_Earth_Comparison.png

(created by NASA)





13




The unique benefts

o Solar Thermal

4



Heating accounts or a signifcant proportion o the world’s total energy demand.

The building sector alone consumes 35.3%, o which 75% is or space heating and

domestic water heating (IEA, 2006). Besides buildings, there is substantial heat con-

sumption or industrial processes and heat-intensive services.

In Europe, the fnal energy demand or heating and cooling (49%) is higher than orelectricity (20%) or transport (31%) (EREC, 2006).

In the past, the heating sector has been traditionally neglected in the energy policy

debate. Now it is becoming increasingly evident that the renewable heating and cool-ing (RES-H/C) sector must play a major role in reaching the European policy goals in

terms o reducing greenhouse gas emissions, increasing the renewables share in theenergy mix, and reduction o the dependency on imported ossil uels.

O course, RES-H/C deployment must go hand in hand with a substantial improvement

in the energy efciency o buildings and o heat consuming processes. It is imperative

that both pathways develop as rapidly as possible to dramatically increase efciencyand to replace the remaining heating and cooling demand by RES. Higher efciency

values create the neccessary conditions or a ully renewable supply o thermal energy

demand, reeing the scarce ossil uel resources or other purposes where they are less

easily replaceable.

During the coming years and decades, ossil uels and nuclear power will become

increasingly scarce and expensive as a result o the exhaustion o natural resourcesand the climate change mitigation policies. This process has obviously already started.

Thereore, using ossil uels or electricity as the main resource to achieve the low

temperatures required or heating and cooling buildings will become too expensive or

most people and will be seen as an unacceptable squandering o resources.

Figure 7: Final Energy demand in the European Union. (Source: EREC, 2006)

4 The unique benefts o Solar Thermal

4 The unique benefts o Solar Thermal

14



Certainly, the use o biomass and heat pumps will rise signifcantly. However, scarce

biomass resources are needed to ulfll the demand rom other energy and non-energy

felds, while a wide deployment o heat pumps as a main source o heating would im-

ply a massive increase in electricity consumption, with strong economic and environ-

mental external costs. Thereore, solar thermal (ST) will become an indispensable and

crucial pillar o the uture energy mix or heating and cooling.

Within the RES-H/C portolio, ST has unique and specifc benefts:

ST always leads to a direct reduction o primary energy consumption•

ST can be combined with nearly all kinds o back-up heat sources•

ST has the highest potential under the RES-H/C-technologies and does not rely on•

fnite resources, needed also or other energy and non-energy purposes

ST does not lead to a signifcant increase in electricity demand, which could•

imply substantial investments to increase power generation and transmission

capacities

ST is available nearly everywhere. Current limitations, or instance at very high•

latitudes or in case o limited space or heat storage, can be largely overcome

through R&D, as shown later in the present document

ST prices are highly predictable, since the largest part o them occur at the mo-•

ment o investment, and thereore does not depend on uture oil, gas, biomass, or

electricity prices

The lie-cycle environmental impact o ST systems is extremely low•

ST replaces (mainly imported) natural sources with local jobs. Wherever the ST•

hardware will be produced in the uture, a large portion o the value chain (distri-

bution, planning, installation, maintenance) is inherently related to the demand

side

Solar thermal is thereore the absolute best option or ulflling the long-term heating

and cooling supply. In the long-term, the goal will be to meet our heating demand as

much as is technically possible with solar energy; preserving the scarce electricity,

biomass and ossil uel resources or instances where solar heating is not yet availableat acceptable costs.

In principle, most people would agree with these statements. However, in the past

many did not regard solar thermal as an important pillar o the energy supply system

since they could not imagine the huge technological potential o solar thermal. These

advantages will be described in the ollowing chapters.

15



Ocular projection of the sun with large sunspots using a spotting scope

Source: http:/ /de.wikipedia.org/wiki/Bild:Sun_projection_with_spotting-scope_large.jpg(GNU Free Documentation license; Photographer: SiriusB)

16

Solar Heating and Coolingor a Sustainable Energy Future in Europe



17



A technological perspective onSolar Thermal potential

5



The independent Global Climate Decision Makers Survey (GCDMS, 2007) presentedin December, 2007 at the UN Climate Change conerence in Bali showed that, amongapproximately 20 carbon reduction technology options, solar thermal and passivesolar are considered over the next 25 years to be technologies with the highest carbonreduction potential without unacceptable side eects. This shows that politicians andexperts are becoming increasingly more aware o the importance o harnessing thepotential o ST.

Despite these realized benets, widespread usage is still a long way away and wemust intensiy our eorts in order to make the ST potential ully easible. Today, STis mainly used in the heating o domestic hot water. The share o systems which aresupporting space heating is presently small, yet growing. Up until now, ST systems are

almost exclusively used in residential homes. Thereby we must ollow our strategiessimultaneously to develop the ull potential o ST.

1. The number o solar thermal systems has to be sharply increased (market deploy-ment measures are needed)

2. The share o solar thermal energy which is covered by a ST system per build-ing has to be increased step-by-step up to 100% (market deployment and R&Dmeasures are needed)

3. ST has to be introduced in new market segments like the commercial and indus-trial sector (R&D and market deployment measures are needed)

4. New ST applicat ions, e.g. Solar Assisted Cooling and process heating have to bedeveloped (strong R&D and market deployment measures are needed)

ST is becoming more and more popular in a growing number o countries worldwide.The worldwide market or ST systems has been growing continuously since the begin-ning o the 1990s. In Europe, the market size nearly tripled between 2002 and 2006.Even in the leading European ST markets Austria, Greece and Germany, only a minorpart o the residential homes are using ST. In Germany, about 5% o one and twoamiliy homes are using ST energy.

Figure 8: Market development o solar thermal in the European Union. (Source: ESTIF, 2007)

5 A technological perspective on Solar Thermal potential


5.1 Current trends in the ST market

18



Other European countries are now systematically developing their ST markets as well,such as Spain, France, Italy and the UK. However, both within Europe and at a globallevel, the ST market development has been previously characterized by huge gaps be-tween a small number o rontrunner countries and a large number o countries whichare still in the star ting blocks.

The chart above shows that, in absolute terms, China by ar comprises most o theST market worldwide. In spite o the strong technological leadership o the EuropeanST industry and the high variety o available ST technology, Europe has only a smallmarket share worldwide, whereas North America and Oceania still play an insignicantrole. Among the “others”, ST is mainly used in Turkey, Israel and Brazil.

The chart below reviews the same data, but per capita.

Figure 9: Annual newly installed capacity o fat-plate and evacuated tube collectors in kW th by economicregion. (Source: IEA, 2007)

Figure 10: Annual newly installed capacity o fat-plate and evacuated tube collectors in kW th per capita.(Source: IEA, 2007)

19



Taking into account the population, the Chinese leadership is less strong, whileOceania, Europe and Japan are in a better position. However, the huge imbalancebetween dierent regions remains impressive.

Even stronger gaps are registered within Europe. Solar Thermal Markets 2006 in Europe

Figure 11 shows that Germany has by ar the biggest ST market, ollowed by Austria,Greece, France, Italy and Spain. All o the other European countries have relativelysmall market as o now. However, this order is dierent i one looks at the ST mar-ket per capita. While Cyprus enjoys particularly avourable conditions, Austria is arather average country, considering its climate, building stock and prevailing heatingsystems. However, with over 250 kWth by Mid 2008 per 1000 inhabitants, Austria ismore than six times ahead o the EU average, and 10-40 times ahead o most othercountries, including those with high potential such as Italy, Spain and France. It is evident that these huge gaps between neighbouring countries are not due to suchdramatically dierent technological barriers or objective conditions, but mainly to

market dynamics and political ramework conditions.

Even in Austria, with its comparatively large stock o ST capacity, there is not the slight-est sign o market saturation. I the current trend in the Austrian ST market continues, Austria will reach the per capita level o Cyprus in less than a decade.

Figure 11: ST capacity installed in 2006 in dierent European countries total (orange bars) and per capita(blue dots). (Source: ESTIF, 2007)


20



ST will cover 50% o the heating demand in Europe in the long term when ST will be used in al-most every building, covering more than 50% o the heating and cooling demand in reurbishedbuildings and 100% in new buildings. ST will also be used in district heating systems, and incommercial and industrial applications with many new and improved ST technologies. But whatcould be the short-medium term ST potential?

With the current ST technologies, the European short-medium term ST potential is certainlysubstantially higher than the level o Austria (ca. 250 kWth per 1.000 capita). Also, it is higherthan the level o Cyprus today, where solar thermal is currently used almost exclusively ordomestic hot water (DHW) preparation. Moving the entire EU to the current level o Cyprus wouldimply multiplying the ST capacity in operation by 15 in the EU. This shows that, or the next twodecades, the available technology is denitely not a actor limiting growth! Technological devel-

opment will also certainly help speed-up the market penetration o solar thermal in the short-medium term. However, the main barriers to growth are still o a non-technological nature.

ESTIF sets the goal o one m² solar capacity in operation until 2020 as a short-medium goal,which is equivalent to a capacity o 700 kW th per 1000 capita. ESTIF’s Solar Thermal Action Planor Europe (www.esti.org/stap) oers a systematic analysis o the barriers to growth o solar ther-mal with existing technologies, and guidelines how to overcome them through industry actionsand public policies. It can be expected that the upcoming EU Directive will reduce these gaps andallow or a more rapid exploitation o the short-medium term ST potential. The increased marketvolumes will provide the ST industry the means or a substantial increase in R&D investments.This will extend the boundaries o the ST potential, opening the way or the implementation o theESTTP’s vision or 2030.

Compared to other continents, Europe has the most sophisticated market or di erent solar ther-mal applications, with a relatively wide mix o dierent applications such as hot water prepara-tion, space heating o single- and multi-amily homes and hotels, large-scale plants or districtheating as well as a several pilot systems or air conditioning, cooling and industrial applications.

However, also in Europe, the majority o the new ST systems are installed on residential homesor heating domestic hot water (DHW) only, with typical solar ractions (i.e. the share o DHW de-mand covered by solar) in the range o 40-80%. Nevertheless, there is already a clear tendency

towards combined ST systems or DHW and space heating support in countries like Germany and Austria, where 50% or more o the newly installed systems are combined systems.

Additionally, in markets like Spain, France and Austria, large ST collective systems or multi-amily homes have a signicant share. The systematic development o the market or collectiveST systems is important to reach the short-medium term goals, since the majority o the Europeanpopulation is living in such homes.

5.2 Short-medium term ST potential

5.3 Main applications in short-medium term

21



By overcoming a series o technological barriers, which are analyzed in detail below, itwill be possible to achieve a wide market introduction at competitive costs o advancedST applications like:

Solar Active Building, covering at least 100% o their thermal energy with solar,•

and in some cases providing heat to neighbours

High solar raction space heating or building renovations•

Wide use o solar or space cooling•

Wide use o solar or heat intensive services and industrial process heat, including•

desalination and water treatment

These are the key elements o the ESTTP Vision, Deployment Roadmap and StrategicResearch Agenda discussed below.

Figure 12: Growth in solar thermal energy use in dierent scenarios. (Source: ESTIF, 2008)

5.4 Medium-long term ST potential (advanced technologies)


22



By implementing them, the potential or economically viable ST usage can be substan-tially expanded. This expansion is refected in the ollowing, simplied diagram.The lower curve (orange area) is a “business as usual” scenario based on a moder-ate growth rate. The middle curve (green area) is a scenario based on an advancedmarket deployment o current ST technologies through strong support policies. Thisleads to relatively high growth rates in the rst period, but ater a certain period o timethe achievable potential with current technologies begins to become saturated andthereore the growth in capacity starts to stagnate at a relatively low level.

The higher curve (gold area) assumes both an advanced deployment o current tech-nologies and strong private and public R&D investments. The technological progressleads to a ull exploitation o the ST potential, thus using solar energy to ulll a

substantially higher share o the total demand or heat and cold. Saturation is reachedlater, and at a higher level o capacity.

Based on political support mechanisms, technical developments based on increasedR&D and on independent report1 calculations o the ESTTP show realistic growths rateso 20% in the solar thermal market.

These growth rates would lead to an installed capacity o 970 GW th by 2030 in theEU. Based on the EU-25 heat demand o the year 2004 (AEBIOM, 2007), these solarthermal collectors could supply about 8% o the total heating demand. Combinedenergy conservation measures and increased eciency in the building sector (-40%heat demand compared to 2004) would enable solar thermal systems to supply about20% o the overall heat demand in EU-27 by 2030.

The long-term potential (2050) o solar thermal is to provide or about 50% o the EU´sheat demand. In order to achieve this goal an installed capacity o 2576 GW th or 8 m²per inhabitant would be necessary.

1 Sustainability Report o the Swiss Sarasin Bank

23



24

Sun photo with hydrogen alpha flter

Source: http:/ /de.wikipedia.org/wiki/Bild:Son-1.jpg(GNU Free Documentation license)




25



Vision 20306



The ESTTP’s main objective is to create the right conditions in order to ully exploitsolar thermal’s potential or heating and cooling in Europe and worldwide. This wouldensure long-term technological leadership o the European industry.

The achievement o this potential will not be completed by 2030. However, under posi-tive ramework conditions, it will be possible to substantially expand the use o solarthermal, and to set the technological basis or achieving ull potential in the ollowingtwo decades.

As a rst s tep or the development o the Deployment Roadmap and o the StrategicResearch Agenda, the ESTTP has developed a vision or solar thermal in 2030. Its keyelements are to:

establish the• Active Solar Building as a standard or new buildings by 2030 - Ac-tive Solar buildings cover 100% o their heating and cooling demand with solarenergy;

establish the• Active Solar Renovation as a standard or the reurbishment o exist-ing buildings by 2030 - Active Solar renovated buildings are heated and cooledby at least 50% with solar thermal energy;

satisy with solar thermal energy a substantial share o the• industrial process heatdemand up to 250°C, including heating and cooling, as well as desalination andwater treatment and a wide range o other high-potential processes; and

achieve a broad use o solar energy in existing and uture• district heating andcooling networks, where it is particularly cost eec tive.

The ollowing sections discuss cer tain economic implications o this vision. Subsequentchapters consider the Deployment Roadmap or the dierent applications, and theStrategic Research Agenda required to achieve this vision.

Solar thermal energy replaces imported uels with local jobs. There would also bemany other economic benets resulting rom the ull exploitation o the ST potential.By implementing the ESTTP Vision, the EU would save approximately 47 Mtoe per

year by 2030, and 126 Mtoe per year by 2050. The economic value o this would besignicant, but cannot be quantied without knowing the prices and quantities o oil,gas, electricity and biomass or heating in the years discussed.

Beyond a reduction in energy bills, the advantage o highly predicable prices or heat-ing and cooling must also be considered. The majority o ST costs are incurred at theinitial investment stage, so can be easily predicted. Conversely, the total costs o allother heating supply technologies depend largely on the unpredictable uture develop-ment o uel and/or electricity prices. I ST were to be ully exploited, it would signi-cantly reduce the macro-economic risks linked to the fuctuation o energy prices andthe security o energy supply.

6 Vision 2030

6 Vision 2030

6.1 Macro-economic benets

26



A high share o solar energy in the heat supply will also have benets in terms o socialpolicy. The high oil prices have become a substantial threat to low-income house-holds in Europe. Several Member States recently increased nancial support to thosehouseholds that cannot aord the current heating oil and gas prices (“heating aid”, orexample the French Government’s announcement on 11 November 2007 to doubleheating aid rom €75 to €150 per household, thus earmarking a total o 70 millionEuro to oset the negative economic eect o high ossil uel prices).

Currently, at least 80% o the solar thermal value chain serving the EU market is basedin the European Union, including:

over 90% o manuacturing;•

almost 100% o sales and marketing; and•

100% o installation and maintenance (which are inherently local and always•

create local jobs and wealth).

Only raw materials are largely imported (see below or more de tails on employment).

By helping to increase the uptake o solar thermal, the ESTTP improves Europe’s tradebalance and lowers the running costs o both businesses and private households.

Improved competitiveness is necessary or moving rom early markets to mass mar-kets. Under positive boundary conditions, solar domestic hot water is oten alreadycost-competitive with ossil-uel based technologies, i considered over the lietimeo the solar system. Applications or space heating in multi-amily houses, as well assolar assisted district heating are also close to competitiveness. These applicationshave the potential or short payback times. They are reliable, but their higher initialinvestment costs means they appear more expensive to potential purchasers whencompared with conventional heating systems. However, this is not the case i cos ts arecompared over a ull lie cycle.

Practical experience shows that cost competitiveness does not automatically lead to amass market. There are plenty o potential energy eciency measures with a return on

investment o only two or three years, and still they remain unused. In economic terms,this may be due to incorrect inormation about the perceived transaction costs. Inpractical terms, it may be due to iner tia, lack o inormation, lack o nancial resourcesand other priorities, or the eec ts o publicity.

6.2 Cost competitiveness

27



This means that cost competitiveness does not necessarily create a mass market ora product. However, it can be assumed that moving towards a mass market will beeasier, as return on investment times become shor ter.

The table below shows a range o prices or heat generated by a solar thermal system,compared to the current price o gas and elec tricity or the end user, and the priceprojected or 2030. Infation is not taken into consideration.

Cost in €-cent per kwh

Today 2030

CentralEurope

SouthernEurope

CentralEurope

SouthernEurope

Solar thermal 7 - 16 5 - 12 3 – 6 2 - 4

Natural gas 8,5 - 29 17 - 58

Electricity 7 - 33 14 - 66

The costs o solar heat include all taxes, installation and maintenance. The spread iswide, because the total costs vary strongly, depending on actors such as:

quality o products and installation;•

ease o installation;•

available solar radiation (latitude, number o sunny hours, orientation and tilting•

o the collectors);

ambient temperature; and•

patterns o use determining the heat load.•

By 2030, it is assumed that technological progress and economies o scale will lead toaround a 60% reduction in costs.

The current costs o gas and electricity are based on Eurostat data, pertaining toprivate households or the second quarter o 2007 with a small load, and includingall taxes. The cost o heating equipment is not taken into account, as this is deemedto be a necessary back-up or a solar thermal system. To reduce the eect o outliers,

the cheapest and the most expensive countries have not been taken into consideration.The current price levels are somewhat underestimated. Eurostat has data rom all 10Eastern European new Member States and rom Croatia. However, it only has guresrom 4 o the EU-15 countries, where nal user prices tend to be higher. It should alsobe stated that larger cus tomers, such as big business, are able to obtain lower prices

6 Vision 2030

28



and do not pay VAT. The assumption underlining the 2030 prices is an average 3%annual real increase in the cost o electricity and associated prices, which is clearlylower than during the last decade. Infation is not taken into consideration.

While important cost reductions in solar thermal can be achieved through R&D andeconomies o scale, the table shows why ESTTP’s priority is to enable the large-scaleuse o solar thermal energy through the development to mass market o new applica-tions, such as Active Solar Buildings, solar cooling, process heat, and desalination.

Over the last decade, investment cost reductions o around 20% have been observedor each 50% increase in the total installed capacity o solar water heaters. Combi-sys-tems in particular have beneted rom these cost reductions, and have increased theirmarket share. Further RD&D investment can help to drive these costs down urther.Cost reductions are expected to stem rom:

direct building integration (açade and roo) o collectors;•

improved manuacturing processes; and•

new advanced materials, such as polymers or collectors.•

Furthermore, cost reduction potential can be seen in increasing productivity by themass production o standardised (kit) systems, which reduce the need or on-siteinstallation and maintenance works.

Figure 13: Typical cost ranges o domestic water/space heating with solar thermal, gas and electricity.(Source: ESTIF, 2008)

29



Advanced applications, such as solar cooling and air conditioning, industrial applica-tions and desalination/water treatment, are in the early stages o development, withonly a ew hundred o rst generation sys tems in operation. Considerable cost reduc-tions can be achieved i R&D eort s are increased over the next ew years.

Figure 14: Development o specic costs and installed capacity or small solar thermal systems(orced circulation) in central Europe. (Source: ITW, University Stuttgart)

Figure 15: Indication o the current state o deployment o solar thermal applications rom development toapplication in the mass market. (Source: AEE INTEC, 2008)

6 Vision 2030

30



As is the case with other renewable energy industries, solar thermal has become a jobmotor in Europe. The solar thermal sector in Europe currently provides 28,000 ull-timepositions in a range o sectors, including manuacturing, marketing, system designand engineering, installation and ater sale services. Provided that Europe is able torapidly increase its share o the global market and expand its domestic market, thisgure is expected to increase to 220,000 by 2020.

The ollowing table shows gures or production, turnover and employees or some othe leading European solar thermal manuacturers.

Company Production Turnover(EUR million)

Employees

Tm2 Pro-ducts

Total Solarthermal

Total Solarthermal

Alanod (DE) 1400 C n.a. 25 milEUR

440 35

BBT (DE) 260 FPC,ETC

2800 ~ 11% (1) 12900 n.a.

BlueTec (DE) 1100 C 25 100% 20 20

GREENoneTEC(AT)

760 FPC, A,ETC

80 100% 360 360

KBB (DE) 330 A, FPC 100% 65 65

Paradigma/Ritter

(DE)

100 ETC 47% 264 160

Schot t (DE) 28 ETC 2200 n.a. 6900 150

Schüco (DE) 200 FPC 1600 ~ 3% 4700 400 (2)

Solvis (DE) 160 A, FPC 47 48% 120 n.a.

SunMaster (AT) 120 A, FPC 18 100% 83 83

Thermomax (UK) 93 ETC 26 100% 220 220

ThermoSolar(DE/CZ)

200 C, A,FPC

20-25 > 80% 140 120

TiNOX (DE) 480 C 10 100% 20 20

Vaillant (DE) 65 FPC,

ETC

2000 ~ 5% n.a.

Viessmann (DE) 345 FPC,ETC

1400 ~ 20% 7400 n.a.

Wagner (DE) 170 FPC,ETC

120 40% 250 170

Wol (DE) 95 FPC 230 25% 1200 40

6.3 Employment

FPC: fat-panel collectors; ETC: tube collectors; A: Absorber; C: Absorber Coating.1) Renewables segment overall;2) ST and PV;Source: W.B. Koldeho, August 2007.

Table: Production, turnover and employees or selected European collector and absorber manuacturers in2006. (Source: Sarasin, 2007)

31



The table above is by ar not complete: There are many more collector and absorbermanuacturers in the EU. Within the manuacturing sector, other jobs are created in thesupply industries (metal, glass and insulation material), as well as in the componentproduction sector (storage tanks, piping, controllers and transer fuids). In total, thereare about 8,000 ull-time positions in the ST manuacturing sector. Most o these jobsare in marketing and distribution, systems design and engineering, installation andater-sales services.

Manuacturing represents limited labour costs, while the orange areas relate mainly to

local labour-intensive services.

It is crucial to maintain the technological leadership o European manuacturers, inorder to ensure a signicant market share o the u ture global ST market. Global annualsales are currently in the region o 18 GW th (25 million m2) per year. And the Euro-pean share o the present global market is only around 15-20%, due to the dominanceo the Chinese low tech, low cost demand, which is mainly served by local producers.

To make a projection on uture employment rates in the ST sector, it is necessary tomake certain assumptions on:

the global and EU domestic market development;•

the export capacity o the EU ST industry; and•

labour productivity increases.•

Figure 16: Shares o costs o Solar Thermal systems (small domestic hot water system, orced circulation,estimated EU average). (Source: ESTIF internal survey)

6 Vision 2030

32



Assuming an average annual growth rate o 20%, a global market size in the rangeo 150 GWth (250 million m2) per year can be projected or 2020. This is a relativelyconservative assumption, taking into account that Europe recently experienced higherrates or several years. Whereas North America and other parts o the world have yet tobegin serious ST development.

By increasing their technical leadership, European manuacturers could increase theirshare o the global market rom the present 15-20% to 40%. O course, this largelydepends on R&D progress by European companies, compared to global competitors.This assumption is ambitious but easible, when taking into account an increase inthe demand or high-quality European products, which can be expected in North andSouth America, advancing Asian countries, as well as in Europe itsel. This would lead

to annual sales by European manuacturers in the range o 70 GWth (100 million m

2

);a large percentage o which would be exports. Even making conservative assumptions(very high productivity increases), this would create approximately 220,000 ull-time

jobs, 100,000 o which would be in manuacturing, and 120,000 in ST services (mar-keting, distribution, system design, installation and maintenance).

Figure 17: Solar Thermal jobs in Europe. Eects on uture employment based onthe 20% market growth rates discussed earlier. (Source: AEE INTEC, 2008)

33



Europe is without any doubt the worldwide technological leader in solar thermal devel-opment. European companies lead mainly in the ollowing sectors:

Selective suraces or absorbers•

Advanced collector production methods (e.g. laser welding)•

Advanced fat plate collector technology•

High quality vacuum tube collectors•

Process heat collectors•

Stratied hot water storage•

Electronic controllers•

System technology (e.g. solar combi-systems with a burner directly integrated•

into the storage)

Large-scale ST systems combined with seasonal heat stores•

Advanced applications (cooling, combi-systems and industrial applications)•

So, Europe is currently leading in nearly all sectors o ST technology, which explainswhy the manuacturing capacity in Europe is growing enormously, notably in relativelyhigh-wage countries, such as Austria, Germany, Denmark and the UK.

Moreover, some European countries, including Sweden, Denmark, Germany and Aus-tria are leaders in low-energy building technologies, which are a prerequisite or a highratio o solar thermal in heating systems. In this area, strong cooperation with other

technology platorms, such as ECTP and SusChem, is necessary.

The signicant growth seen in the European market over the last decade has helpedto consolidate this technological advancement. However, the current market size inEurope (around 2 GWth new installed capacity per year) is s till tiny, compared with thecurrent Chinese market (12.6 GWth per year) and the expected uture global ST market,which could reach 100-200 GWth within a decade.

6.4 International competition and technological leadership

6 Vision 2030

34



However, in the context o such dynamic market growth and technical development,maintaining technological leadership cannot be taken or granted. In order to maintainthis European technological leadership, it is crucial or Europe to invest serious moneyin ST R&D. Internal demand in Europe also needs to grow quickly enough to make itthe largest market worldwide (per capita). The ESTTP is playing a crucial role in sup-porting and meeting both these challenges.

Figure 18: Contribution o solar thermal to EU heat demand by sector, assuming that the total heat demandcan be reduced by energy conservation and a 40% increase in eciency by 2030.(Source: AEE INTEC, 2008)

35



This image o the sun reveals the flamentary nature o the plasma

connecting regions o dierent magnetic polarity

Source: http:/ /commons.wikimedia.org/wiki/Image:171879main_LimbFlareJan12_lg.jpg(created by NASA); Author: Hinode JAXA /NASA)

36




37



Deployment roadmap7



This chapter outlines a roadmap or the deployment o solar thermal energy towardsthe implementation o the V ision 2030 discussed above.

The basic principle o solar thermal is always the same, and similar components andtechnologies are used in all applications. However, there are certain technological andmarket development challenges. This chapter addresses key areas or the use o solarthermal energy, which include buildings, industrial processes (desalination and watertreatment) and district heating. An introduction to each o these sectors is ollowed bya table giving an overview o the current situation, and the predicted stage o develop-ment in 2020 and 2030, taking into account a number o technological and marketdevelopment parameters.

This Deployment Roadmap serves as the basis or the detailed Strategic Research Agenda, assuring that the proposed research elds are embedded into the requirementsarising rom expected market needs. The Strategic Research Agenda (see Chapter 8)describes in detail the necessary R&D work.

It is expected that the energy and climate crisis will drastically change the heatingmarket over the next two decades. In new buildings, we expect a tightening o energyperormance requirements, including the obligatory use o renewables, which will beincreasingly required by governments and the market. In the existing building stock,energy savings will become the key driver or renovations, and district heat operatorswill become more interested in, and possibly be orced to increase the share orenewables.

For industrial process heat and cooling, the key driver will be the need to reduce grow-

ing energy costs, and possibly the cost o emission allowances at the carbon market,as long as they are applied to heat consuming processes.

All these developments will lead to a sharp increase in the use o solar thermal tech-nologies and the subsequent need or new and advanced technologies in this eld.

As seen above, most solar thermal systems are currently dedicated only to hot waterproduction, which has traditionally been the main application or solar thermal. Over

the last decade, “Combi-systems,” which provide both hot water and space heating,have become a standard product, and have gained a considerable market share in theleading markets o Central and Northern Europe. Typically, the average combi-systemcovers 70-90% o the hot water demand and 10-20% o space heating demand,depending on a number o external actors.

The ESTTP vision is to es tablish the Active Solar Building as a standard or new build-ings by 2030. Active Solar Buildings cover 100% o their demand or heating (andcooling, i any) with solar energy.

For existing buildings, the aim o the ESTTP is to os ter the Solar Active Renovation,achieving massive reductions in energy consumption through energy eciency meas-ures and passive solar energy. The aim is also to cover substantially more than 50% othe remaining heating and/or cooling demands with active solar energy.

There are already many Active Solar Buildings with a proven track record in CentralEurope. In 1989, the rst one-amily house covering 100% o its heating requirements

7 Deployment roadmap


7.1 Towards the active solar building

38



with solar energy was created in Switzerland. More recently the rst multi-amily build-ings with 100% solar thermal coverage were introduced.

The requirements are high eciency values, a su ciently large solar collector area anda seasonal heat storage sys tem, enabling solar energy accumulated in the summermonths to be used during the winter.

Heat storage represents a key technological challenge, since the wide deploymento Active Solar Buildings largely depends on the development o cost-e ective andpractical solutions or seasonal heat s torage. The ESTTP vision assumes that, by 2030,heat storage systems will be available, which allow or seasonal heat storage with anenergy density eight times higher than water. In other words, to store the same amounto energy, 8 times less volume than water will be required.

For solar collectors, signicant improvements are still possible, particularly in terms ocost reductions and design. However, low temperature collectors, which are usuallyused on buildings, are already very ecient.

High energy eciency values can be reached through:

high insulation standards, which reduce losses; and•

optimal architecture, which integrates passive solar measures, such as ac tive•

windows, shading or ventilation systems.

Furthermore, the productivity o solar thermal systems is enhanced by heating andcooling systems that require a low temperature dierence between the supply systemand the indoor temperature, such as radiant suraces, foor heating and cooling, ceil-

ing heating and cooling, and heating/cooling o ventilation air. Most o these solutionsalready exist, but there is still potential or cost reductions, increased perormance andeasier integration.

The demand or cooling in buildings is growing dramatically; and not only in SouthernEurope. Despite the impressive growth rates, solar assis ted cooling is still in the veryearly stages o development. Over the next decade, the rs t Solar “Combi+-Systems,”supplying domestic hot water, space heating and cooling or buildings will be installed.However, signicant R&D must be carried out in order to exploit the potential or urthertechnological development, which will pave the way or the large-scale deployment osolar cooling. These R&D investments will be benecial or society as a whole, takinginto account that solar assisted cooling will replace highly inecient electrical coolingsystems that consume very expensive and polluting electricity at peak times.

Figure 19: 100% solar heated multi-amilyhouse in Switzerland. Installed capacity 193kWth (276 m² collector area) and a 205 m³

heat storage.(Source: Jenni Energietechnik AG, Switzerland)

39



In the uture, solar active systems, such as thermal collectors, PV-panels and PVT-sys-tems, will be the obvious components o roo and açades. And they will be integratedinto the construction process at the earliest s tages o building planning. The walls willunction as a component o the ac tive heating and cooling systems, supporting thethermal energy storage through the application o advanced materials (e.g. phasechange materials). One central control system will lead to an optimal regulation othe whole HVAC (heating, ventilation and air conditioning) system, maximising theuse o solar energy within the comort parameters set by users. Heat and cold storagesystems will play an increasingly important role in reaching maximum solar thermalcontributions to cover the thermal requirements in buildings.

Key areas or technological development

While a very small number o Solar Active Buildings have already been showcased,making them a mainstream building standard by 2030 will only be possible i signi-cant technological progress is achieved in the ollowing areas:

High-efciency solar collectors• will increase the energy gained under winterconditions, while maintaining high levels o durability and increasing the cost-eciency o the manuacturing and installation process.

New• compact, time indierent thermal storage technologies will signicantlyreduce the space required or heat s torage devices. This will lead to cheaper andmore practical seasonal heat storage, allowing large amounts o heat accumu-lated during the summer to be used or space heating during the winter.

Improved•

solar thermally driven cooling systems will make it possible to covermuch o the ris ing demand or air conditioning with solar energy.

Intelligent control systems• o the overall energy fows in buildings will contributeto a reduction in energy consumption and the optimisation o solar energy usage.

The ollowing tables outline the various scenarios and requirements rom now until 2030.


40



RESIDENTIAL/COMMERCIAL, NEW & EXISTING BUILDINGS

2008 2020 2030

TECHNICAL

Fundamental research

Orientation stage or•

Compact Time-indie-rent Storage (CTIS)

Orientation to start R&D•

on new or innovativematerials (low cost/

high requirement)

Second generation•

compact storagestarted

Cooling option or•

domestic purposesreaching conclusion

Full undamental R&D•

completed or CompactTime-indierent Storage

New materials proven•

to be usable or STapplications

Building integration ai-•

med at integration withbuilding elements andintegration with otherequipment

Next generation•

Industry developments

System development or•

cooling systems

Combi-systems and•

system integration

Price/perormance•

optimisation on SDHW-systems

Building integration•

Product development to•

commercial compact/ time-indierent storagesystems or wide use incombi-systems

Cooling options as•

integrated units ordomestic sector

New materials incor-•

porated in productdevelopment (expectedimpact on cost price/ perormance ratio tolead to a 25% impro-vement)

Greater adaptation to•

the building sector,urther integration withheating systems androo

Integrating compact/ •

time-indierent storagesystems in existingbuildings

41




2008 2020 2030

Identied demonstration/lighthouses

Cooling or 10 kW +•

systemsDemo compact heat•

storage rst generation

Third generation combi-•

system, using CTIS(100% DHW+SH)

High perormance reno-•

vation; passive house

standard or renovation

Plug and play•

Active solar renovation•

with less than a 75%energy requirement

100% market applicable technologies

Solar domestic•

hot water systems(SDHW) (Solar raction50-90%, depending onlatitude)

First generation combi-•

system deployed on aairly large scale in AT

+ DE (solar raction ataround 75% or DHWand 10% or spaceheating)

SDHW systems•

Solar cooling or com-•

mercial sector

Solar combis (second•

generation - DHW80-90+%, SH25-50%+ dependingon latitude)

Compact heat storage•

in 2nd generation in ullmarket deployment.

Cooling or all building•

types available

Combi systems provide•

100 % solar raction

Combi systems with•

cooling possibilities

Solar systems integ-•

rated with ventilationsystem, heat pumpsetc.

Standards and certication

Calculation methods or•

EPBD through CEN, TC312, + upgrade o CENseries

Keymark on collectors•

– widespread systemscertication (Keymark)initiated

Installation qualication•

in some countries

Combi-systems in•

Keymark

Standard and certica-•

tion process or cooling

in nal stageSeparate standards or•

CTIS in preparation

Full standards and•

certication or all STapplications in newbuild sector

Certicates based on•

standards or productsand systems on instal-lation quality


42




2008 2020 2030

Perormance and durability

First generation o sys-•

tems and componentshave proven 15-25 yrs+ lie expectancy

Price/Perormance inc-•

reased overall by 35%check costs gures withnew chapter comparedto 2007

Durability proven to be•

> 20 yrs on system level

Add remark on LCA and•

the need or materialswith less environmentalimpact

New materials reduced•

burden on scarcer rawmaterials

Recycling standard in•

design o systems

Durability to maintain•

on 20-25 yrs lietime

expectancy


2008 2020 2030

MARKET

Share o solar in dierent applications and regions

< 1-50% o SDHW sys-•

tems in new buildings,depending on localpolicies (not climaterelated)

Combisystems- rst si-•

gnicant market sharesentries in D & Austria

> 90% o EU ST market•

in small buildings (hou-ses or 1-2 amilies).In a ew regions, rstsignicant penetration

into new large buildingsExisting buildings:•

High share only insome regions

25-75% o new•

buildings use SDHW(standard now or allnew buildings)

Existing buildings:•

Penetration o 10% inall Europe. Best regionsreach 80% penetration

Combi systems are•

commonly used in allcountries (o whichmany combine themalso with cooling) >

50% o the ST marketconsists o CombiSystems

Wide use o ST also in•

large buildings

All new buildings rely•

on their heating, coo-ling and comort systemon integrated solarthermal systems

Integration with building•

construction and otherinstallation components(like ventilation, heatpumps) are commonpractice

Buildings without a•

solar system catch

people’s eyes: childrenask “why doesn‘t thathouse have a solarcollector?”

43




2008 2020 2030

Education o proessionals

Training programmes•

are set-up in mostcountries; however theimplementation in theinstaller sector showsdelays. Nr o trainedinstallers is consideredtoo low or market

deployment ambition

In most regions, still•

very low awareness &training among heatingengineers, architects.The latter partly stillalmost hostile

Education in vocational•

schools and highereducation is gettingshape

Solar Thermal is normal•

part o the curriculum atall levels in educationsystem

Knowledge base at ins-•

tallers level is adequate

Complementary•

trainings are oeredor combi-systems andcooling

Solar Thermal is normal•

part o the curriculum atall levels in educationsystem

Regulatory issues

Ater having been•

neglected or decades,RES-H is now rmly onthe EU agenda, withrst results in terms oconcrete legislation atnational and regio-nal levels. Future EUdirective will, or therst time, orce MemberState to set targets thatalso cover ST

Against the background•

o new legislation onEnergy Perormancerequirements in newbuildings, a ew MS im-plement regulations onenergy perormancesstandards to make STa competitive opportu-nity, whilst others takeurther steps to make STa requirement in newbuildings.

Standards: develop-•

ment towards EU-wideacceptance o CENstandards, rather thanMS national standards

EU has driven the•

regulatory basis orobligations in newbuildings and majorrenovations; at thisstage to provide aminimum o 50-100%o domestic water and25% o space heating / cooling rom solar

All systems required•

to meet CE and SolarKeymark requirements

and standardsEnergy perormance•

requirements or reno-vation and obligationsin some regions

Building regulations do•

not allow the use o ex-ternal energy sources.

All energy needs to beproduced on site byrenewables

Standards: EU-wide•

required CEN standardsand certication


44




2008 2020 2030

Price / Perormance

Due to rising energy•

prices, technologicalprogress and eects oneconomy o scale theP/P ratio has improvedand reaches a neutralbalance in comparisonwith most tradition

uels, allowing earlyadaptors to enter

Guaranteed Solar Result•

Contracts and otherST-ESCO solutions areoered only by ew, pe-ripheral market players

Lower solar raction•

options are all compe-titive; the higher solarraction options reacha neutral balance incomparison with mosttradition uels, allowingearly adaptors to entry


Contracts and otherST-ESCO solutions arestandard or mediumand large systems, andpartly used or smallsystems, within a con-text o growing use oESCOs in buildings

P/P ratio very competi-•

tive compared to traditi-onally uelled buildingsor heating and cooling.NPV o Renewableenergy system showhousing cost (includingenergy) considerably

lower compared toliving / working in exis-ting building stock.


Contracts and otherST-ESCO solutions arestandard or all systemsizes, within a contexto wide use o ESCOs inbuildings

Financial support

Most countries (> 75%•

o MS) have some sorto nancial support,usually around 10-20%o the investment costs

Financial support sche-•

mes no longer neededor SDHW. They remainnecessary or very highsolar ractions on spaceheating or cooling andother new market entrytechnologies during de-monstration and marketintroduction stage

There is no nancial•

support required

Image and awareness

Large dierences occur•

over the various MS.

Scattered pattern,depending very muchon local market deve-lopment, public interestand awareness. Overalltendency is that withinthe RE portolio: ren.heating is not high-lighted; public at largeis not aware o largepotential

Solar Thermal is now•

considered a standard

option. No doubt ordebate on eectiven-ess. It is considered astandard and normaltechnology to makebuildings aordableand sustainable

Solar homes are•

considered cheaper,

more comortableand provide long termsecurity o energysupply. All attributing toa positive appreciationand acceptance

45




2008 2020 2030

Market environment

in EP driven markets,•

ST becomes a com-petitive option to reachEP-levels

Heating industry has•

seriously got involvedin ST

Construction industry is•

starting to show inter-est, particularly but notonly in obliged markets

The building and•

installation sector havebecome used to solarthermal. From designto installation the“standard” options areall automatically takeninto account

The technology is con-•

sidered common andstandard

Solar Heating or Industrial Processes (SHIP) is currently at the very early stages odevelopment. Less than 100 operating solar thermal systems or process heat are re-ported worldwide, with a total capacity o about 24 MWth (34,000 m²). Most o thesesystems are o an experimental nature, and are relatively small scale. However, thereis great potential or market and technological developments, as 28% o the overallenergy demand in the EU27 countries originates in the industrial sector, and much othis is or heat o below 250°C.

In the short term, SHIP will mainly be used or low temperature processes, rangingrom 20 to 100°C. With technological development, more and more medium tempera-ture applications, o up to 250°C, will become market easible. According to a recentstudy (Ecoheatcool 2006), around 30% o the total industrial heat demand is requiredat temperatures below 100°C, which could theoretically be met with SHIP using cur-rent technologies, and 57% o this demand is required at temperatures below 400°C,which could largely be supplied by solar in the oreseeable uture.

In several specic industry sectors, such as ood, wine and beverages, transportequipment, machinery, textiles, pulp and paper, the share o heat demand at low andmedium temperatures (below 250°C) is around 60% (POSHIP 2001). Tapping intothis potential would provide a signicant solar contribution to industrial energy require-ments.


7.2 Industrial process heat, including water treatmentand desalination

46



Substantial potential or solar thermal systems exis ts in the ood and beverages, textileand chemical industries, as well as in washing processes.

Among the industrial processes, desalination and water treatment (such as sterilisa-tion) are particularly promising applications or the use o solar thermal energy, asthese processes require large amounts o medium-temperature heat, and are otennecessary in areas with high solar radiation and conventional energy costs.

Clearly, the use o Solar Heating or industrial processes should be par t o a compre-hensive approach, which also takes into account:

energy eciency measures;•

the integration o waste heat into processes; and•

a reduction in heating and cooling demand through the use o a heat exchange•

network.


Since Solar Heat or Industrial Processes (SHIP) is in the initial stage o development,the orthcoming challenges relate to both technology and market deployment. Detailso the most important challenges are set out below.

Medium-temperature collectors and components: An ample choice o solar thermalcollectors is commercially available or low temperatures (operating temperatures upto around 80-90°C) and or high temperatures (>250°C, mainly used or electricitygeneration). The development o cost-eective and reliable medium-temperature col-lectors, which can meet the requirements o most industrial processes, is now required.

Other components o solar systems also need to be adapted to this range o tempera-tures. For example, SHIP would benet rom the development o a new generation ocompact and/or seasonal heat storage systems, and rom advanced controllers.

Figure 20: Processes at dierent temperature levels in dierent industry sectors; Data or 2003, 32 Countries:EU25 + Bulgaria, Romania, Turkey, Croatia, Iceland, Norway and Switzerland. (Source: ECOHEATCOOL (IEE

ALTENER Project), The European Heat Market, Work Package 1, Final Report published by Euroheat & Power)

47



Thermodynamic optimisation o processes: Despite the act that many processes inthe industry operate at temperatures below 100°C, the heat supply o most industrialmachines is currently provided by steam networks operating at between 140 and180°C. This makes the use o solar thermal less attractive, or even impossible.

Switching to lower temperatures would imply signicant investment or inrastructure(network) modication and process redesign, which reduces the attractiveness o solarenergy. New technologies can be developed, which allow processes to operate at lowertemperature. One example is the reduction o bath temperatures in pickling plants. Insome cases, processes can also be e ciently redesigned to make them more compat-ible with the daily and/or seasonal cycle o solar energy supply. Moreover, when new,long-term industrial process acilities are planned, there is always the possibility o

subsequent solar add-ons.

Integrating solar thermal into industrial processes will be a complex process, requiringsupport rom energy agencies and other public players, dedicated to specic industrialsectors.

Need or dedicated design guidelines and tools: Currently only a ew engineer-ing oces and research institutes have experience with SHIP ins tallations. Planningguidelines and tools or typical industrial uses need to be made available to a widercommunity o SHIP-experienced engineers. This would mean that:

other potential users could be oered a SHIP solution;•

system design costs would all; and•

the broader experience would increase the eectiveness o SHIP systems.•

Investment costs: Solar systems are capital intensive, as costs are mainly upront.Industrial companies oten optimise their processes with short-term ROI expectationsthat cannot currently be met by SHIP systems. The wide market development o SHIPwould also require dedicated nancing and contracting solutions; the lack o whichis currently an important barrier to growth. It is crucial, thereore, to rapidly create amarket, in order to reach the minimal critical mass required to start beneting romeconomies o scale.

While RD&D can increase potential and reduce costs in the medium term, nancialincentives and widespread public-unded demonstration projects are an absolutenecessity.

Applied research is necessary in a number o elds, including:

stagnation behaviour and management o large collector elds;•

monitoring o SHIP systems; and•

system optimisation methodologies, to enhance the interaction o solar energy,•

heat recovery and conventional energy sources in various industrial processes.

Due to their relevance and specic technological requirements, desalination and watertreatment are discussed in a separate overview table on the right:


48



INDUSTRIAL SECTOR, PROCESS HEAT

2007 2020 2030

TECHNICAL


Collectors and systems•

or temperature levels o80-250°C

R&D on new/innovative•

materials and con-cepts or heat storage

(such as latent heatand phase-changingmaterials)

R&D on heat storage or•

temperature > 100°C

Simulation tools or•

planning SHIP systems

R&D or storages•

> 100°C

New materials that can•

be used or ST applica-tions

Collectors and systems•

or high temperaturelevels (> 250°C)

Next generation•

Development in industry

Solar Thermal Collec-•

tors with operating tem-peratures o 80-250°C

Systems with water,•

thermal oils, steamand air

Double glazed collec-•

tors and anti-refective-glass

Parabolic collectors and•

CPC collectors

Product development•

or heat storages

Standardisation o•

system concepts

Solutions or stagnation•

problems in big systems

Solar roos or industry•

buildings

Next generation•


Systems or hall heat-•

ing, drying processes,washing and brewing- system size: a ewhundred kW

Systems or cooling e.g.•

winery

Large systems with•

high temperature heatstorages

Large systems o more•

then 2000 kW

Plants in all industry•

sectors (ood andbeverage, textileschemicals) and dier-ent applications (wash-ing, drying, boiling,pasteurising and heattreatment)

100% solar heated•

plants and actories ineach industry sector(operation temperature< 250°C)

SHIP or applications•

that require high tem-peratures (> 250°C)

49




2007 2020 2030


CPC Collectors•

80-120°C

Flat plate collectors•

80-150°C

Vacuum tube collectors•

Systems or processes•

up to 80°C

Collectors with high•

eciency or operat-ing temperatures up to250°C

Solar cooling/heat•

recovery or buildingsector (industry halls

and oce buildings)Methods or the integra-•

tion o solar heat intoeach industry sector’smain processes

Methods or energy•

ecient processes atlower temperature levelsand heat recovery

Monitoring, measure-•

ment and simulationsotware

It is normal in process•

engineering to build aSHIP system or eachprocess with tempera-tures < 250°C


Keymark on collectors• Standard & certi-•

cation process orlow&medium tempera-ture systems in nalstage

Full standards and•

certication or all STapplication in processheat sector


Long experience•

at low temperaturelevels (< 100°C). Firstgeneration systems and

components have aproven lie expectancyo 15-25 yrs +

The monitoring o•

systems that have beenrunning or many yearsshows that there is no

signicant reduction inperormance

New materials reduced•

burden on scarcer rawmaterials


50




2007 2020 2030

MARKET


Worldwide installed•

capacity o about 27MWth (38,500 m²)

About 85 solar thermal•

plants with SHIP world-wide

4 GW• th (5.7m m²)installed capacity inEU27 or low tempera-tures (<100°C)

0.4 GW• th (570,000m²) installed capacity

in EU27 or mediumtemperatures (100-250°C)

15 GW• th (21m m²)installed capacity inEU27 or low tempera-tures (<100°C)

2 GWth (2.85m m²)•

installed capacity in

EU27 or medium tem-peratures (100-250°C)


No special training•

programs available;only regional activities,events or workshops

No knowledge in•

process engineering ointegration o solar heat

Planning guidelines•

or all applications orSHIP are standard ineducation or processengineers

Courses or installers•

and plant constructors

are available

Solar Thermal is a•

standard part o thecurriculum at all levelsin the education system

SHIP is standard in the•

education o installersand plant constructors

SHIP courses are avail-•

able at university

Regulatory issues

Not yet• All systems required•

to meet CE and SolarKeymark requirementsand standards

Renewable energy laws•

oblige the industry touse SHIP or a mini-mum share o requiredenergy

Price / Perormance

Company decision•

makers expect 3-5years amortisation time

New ST-ESCO solutions•

are oered by only aew companies

New business models•

are oered on the mar-kets (guaranteed solaryields and contracting)

Price/perormance•

ratio is very competitivecompared to tradition-ally uelled processesor heating and cooling


Contracts and otherST-ESCO solutions arestandard or all systemsizes, within the contexto a widespread use oESCOs in buildings

51




2007 2020 2030

Financial support

Only a ew special•

regional support pro-grams or building SHIPsystems, or example,

Austria/Upper Austria

National support pro-•

grams or R&D

Financial support•

schemes or SHIP

Support schemes or•

demonstration projects

Support or R&D•

projects

No nancial support•

required

Image and awareness

Solar process heat is•

an unknown technol-ogy. There are only aew companies ocusedon oering systems orsolar process heat

Decision makers in all•

relevant industry sectorsknow about SHIP pos-sibilities

Lighthouse projects and•

best practise systemsinspire condence inthe new technologies

Image campaigns and•

inormation or SHIP

Solar plants are•

considered cheaper,more comortable andprovide long-termsecurity o energy sup-ply. This all contributesto a positive image andacceptance

Market environment

There is no demand•

rom consumers or in-dustry. Finished projectsare demonstrationprojects driven by theR&D sector

Process technology•

does not consider therequirements or solarthermal process heat

Industrial processes•

are not always energyecient (supply tem-perature is on hightemperature level withno heat recovery)

Companies are oering•

turn-key SHIP systemsin cooperation withplant constructors

Trade airs or SHIP•

bring this technologyto industry decisionmakers

Plant constructors•

have specialised SHIPdepartments


sidered common andstandard or plants

Solar Thermal is the•

main heat source orprocesses < 250°C innew build actories.


52



DESALINATION and WATER TREATMENT

2007 2020 2030

TECHNICAL



materials (low cost/ high requirement) orecient thermally-driven heat and masstranser (evaporation

and condensation)Eciency increase o•

solar power generationor desalination pur-poses

Polymer science (unc-•

tional material oils andabrics, heat conduct-ing polymers) - marketresearch

Multi-water quality gen-•

eration; combination odesalination methods

Multi-stage desalina-•

tion; salt production;high recovery - 30 to50%

Develop low cost and•

robust concept or easytechnology transer


materials (low cost/ high requirement) oreven more ecientthermally-driven heatand mass transer

(evaporation and con-densation)

Oil-ree plastic heat•

transer materialscondenser

R&D on system design•

and system compo-nents

Polymer science (unc-•

tional material oils andabrics, heat conduct-ing polymers) - marketresearch

Material research•

or high temperature(rather “medium tem-perature” or “elevatedtemperature”) plasticmaterials

Chemical ree brine•

disposal

Oil and metal ree•

plastic materials orhigh perormance anddurability at low cost

Direct solar thermal•

water evaporation with

integrated heat recovery(large-scale CSP&W)

New desalination proc-•

esses

53




2007 2020 2030

Development in industry

Easy and maintenance•

ree water pre-treatmentor thermal desalina-tion, without oulingand scaling ormation

Envisaged: eciency•

increase o thermal

processes dependingon the capacity

System design or small•

applications

Cost ecient, inte-•

grated transport casingdesigns

House integrated build-•

ing designs; desalina-tion becomes part ohouse technology

Easy-to-build and to•

maintain systems ordecentralised, small-

scale applicationswithout the need orexternal power supply(electricity, uels)

New solar collectors•

and storage adaptedto the needs o solardesalination systems:mid temperature(90-150°C - suitable orhigh resistance againstthe aggressive seasideconditions)

Combination o solar•

thermal desalinationand power generation

Multi-stage desalina-•

tion, using severallinked processes to in-crease recovery by upto 65%

House o the uture:•

design includes solarthermally-driven com-ponents

Grey water recycling•

and sea water de-salination are standard

components o anybuilding


54




2007 2020 2030


About 10 installed•

plants with small scalesolar desalination (1 to50 m³ per day )

100 installed demon-•

stration plants o small(1 to 50 m³ per day)and larger systems(50-500 m³ per day)

First installations o•

solar power generation

and thermal desalina-tion

Small networks o•

renewably driven waterdistribution systems (orcommunities o up to50,000 people)

Highly ecient solar•

thermal power plants

with cooling and desali-nation


Autonomous systems•

up to 10 m³ per daySystems up to 50 m³•

per dayLarge variety o small•

1-200 m³ per day(standard), me-dium (150-2000 m³per day) and large(1500–20000 m³/day)are ready or the market


Solar Keymark on col-•

lectorsStandard or the design•

o systems up to 50 m³

Energy labels or e-•

cient desalinationtechnologies

Full standards and Full•

standards and certica-tion or all componentsin a desalination system

Certied procedures or•

system integration


First generation o sys-•

tems and componentshave proven 15-25years + lie expectancy

Perormance increased•

by 5-10%



Price/perormance•

reduced by another15-25%

Recycling procedures•

or all types o systems


on 20-25 yrs lietimeexpectancy

55




2007 2020 2030

MARKET


Only a handul o instal-•

lations2000 systems are in-•

stalled in aected areasSolar desalination is•

used in all aectedregions to providedrinking water


Systems are sold turn-•

key. Training is providedby the suppliers

Planning guidelines or•

solar desalination arestandard in educationor process engineers

Courses or plant con-•

structors are available

Solar thermal is a xed•

part o the curriculum

Solar desalination is•

standard in the educa-tion o plant construc-tors

University courses are•

available

Regulatory issues

Not yet• All systemsare required•


- 25% share o renew-•

able energy supply orall new installed smalland large desalinationunits obligatory

CEN-standards and•

certication is required

Price / Perormance

Guaranteed Solar•

Result Contracts andother ST-ESCO solutions

are oered by only aew, peripheral marketplayers

Price/perormance•

reduced by 15-35%depending on system

type


Contracts and otherST-ESCO solutions are

standard or all systemsizes, within the contexto widespread use oESCOs in buildings

Financial support

No grants or solar•

desalination available

Implementation o•

grants or desalinatedwater produced by solaror renewable energy

Grants or solar share•

in desalination (CO2-emissions trading, extragrant or solar heat inindustrial processes (in-cluding desalination )

There is no nancial•

support required


56




2007 2020 2030

Image and awareness

Unknown technology• Solar Thermal uel saver•

mode now considered astandard option

Autonomous state-o-•

the-art small desalinati-on systems

Market environment


starting to show interestHouse o the uture:•

design includes solarthermally-driven com-ponents, especially de-salination and cooling



Currently, around 9% o the total heating needs in Europe are covered by block anddistrict heating systems. This share is much higher in a number o countries, especiallyEastern Europe and Scandinavia.

Within district heating systems, solar thermal energy can be produced on a large scaleand with particularly low specic costs, even at high latitudes, such as in Swedenand Denmark. Only a very minor share (less than 1%) o the solar thermal market inEurope is linked to district heating systems, but these systems make the most o large-scale solar heating plants.

The table below lists the larges t solar heating plants (>2 MWth) in Europe - all o themare connected to district heating networks.

Plant,Year in operation, Country

Coll.area[m²]

Size[MWth]

Marstal, 1996, DK 18 300 12,8

Kungälv, 2000, SE 10 000 7,0

Braendstup, 2007 DK 8.000 5.6

Strandby, 2007 DK 8.000 5.6

Nykvarn, 1984, SE 7 500 5,2

Graz (AEVG), 2006, AT 5 600 3,9

Falkenberg, 1989, SE 5 500 3,8

7.3 District heating and cooling

57



Plant,Year in operation, Country

Coll.area[m²]

Size[MWth]

Neckarsulm, 1997, DE 5 470 3,8

Crailsheim, 2003, DE 5 470 3,8

Ulsted, 2006, DK 5 000 3,5

Ærøskøping, 1998, DK 4 900 3,4

Friedrichshaen, 1996, DE 4 050 2,8

Rise, 2001, DK 3 575 2,5

Ry, 1988, DK 3 040 2,1

Hamburg, 1996, DE 3 000 2,1

Schalkwijk, 2002, NL 2 900 2,0

München, 2007, DE 2 900 2,0

Together, these sys tems account or less than 0.5% o EU installed solar thermalcapacity. However, their combined capacity is higher than that o 25,000 small solardomestic hot water systems.

The prevalence o Scandinavian countries is surprising, since solar radiation is lowerin this region. Central and Eastern European countries and district heating systems inSouthern Europe oer much better conditions.

Typical operating temperatures range rom low (30°C) to high (around 100°C) or wa-ter storage. The majority o plants are des igned to cover the heat load over the summermonths (hot water and heat distribution losses) using diurnal water storages. However,some are equipped with seasonal storages and cover a larger part o the load. Theseasonal storages comprise water in insulated tanks (above or below ground) in tenplants, the ground itsel in seven, aquiers in two and a combination o ground andwater in another. More than 80% o the plants are equipped with fat-plate collectors,mostly large-module collector designs. Most plants also have pressurised collectorsystems with an anti-reeze mixture - usually glycol and water - while a ew plants inthe Netherlands have drain-back collector systems.

Several solar district heating systems, especially in Sweden and Denmark, haveground-mounted collector arrays. This can be a very cheap solution, when suracesare available and solar is connected to a network serving existing buildings.

Figure 21: Marstal (DK) 12.9 MWth capacity(18,365 m² collector area), integrated into thelocal district heating system. The world’s largestsolar thermal plant provides 30% o the totalheat demand o a Danish island.(Source: Arcon Solvarme A/S, Denmark)


58



In 1995, the district heating operator in Marstal, on a small Danish island, installedaround 8,000 m² solar collectors and a 2,100 m³ water storage tank to cover up to15% o their annual heating load. The plant was later extended to 18,300 m² (12,8MWth) and is so ar the largest solar heating plant in the world. A recent s tudy o theuture potential or solar district heating in Denmark has resulted in two new plants o3.5 and 5.6 MWth.

In Germany, and Austria, roo-integrated or roo-mounted solar collectors, placed onresidential or service buildings, are oten used.

In the 1980 s, Swedish housing company, EKSTA Bostads AB, pioneered the use oroo-integrated solar collectors in new building areas. At present, EKSTA owns andoperates about 7,000 m² o roo-integrated collectors. Initially, EKSTA used site-builtcollectors, but the latest development, a roo module collector mounted directly on theroo trusses, has been used recently in new and exis ting buildings. This developmenthas resulted in a superior integration into the building process, as well as reducedinvestment costs and improved thermal perormance.

The German large-scale solar heating plants are mainly applied in new residen-tial building areas, using roo-integrated or mounted collectors. Some o the large

projects have so-called “solar roos”. Until 2003, eight projects with seasonal storageand around 50 large to medium-scale projects, with short-term storage, had beencompleted within the Solar thermie2000 programme. In Neckarsulm (Figure 20) andCrailsheim, there are two plants with > 5,000 m² o roo-integrated collectors and inMunich, a new plant with 2,900 m² has been constructed.

The rst large-scale solar plant in Austria – a small local biomass-red heating plantcomplemented with a solar system - was built in Deutsch-Tschantschendor in 1995.Graz is now the large-scale solar city o Austria. The rst plant, built in 2002 (SeeFigure 23), and two newer plants, the largest with > 5.000 m², are connected to thedistrict heating network.

Figure 22: Solar block heating in Neckarsulm, DE.(Source: Stadtwerke Neckarsulm and STZ-EGS, Germany)

59



The most widely implemented application o large solar heating systems in The Neth-erlands is collective housing, institutions and homes or the elderly. Most systems haveabout 100 m² o solar collectors, but some are larger, or example, the “Brandaris”building in Amsterdam, which has 700 m² o rootop mounted collectors. Two large-scale plants are designed with seasonal storage, one is a recent plant with 2,900 m²o solar collectors connected to an aquier s torage in Schalkwijk. There are also solarblock heating plants in France, Switzerland and Poland.


In the short term, the broader use o solar energy within district heating (and cool-ing) systems is mainly a question o policy, namely, incentives, regulation, and thedemonstration o existing technologies. In the medium and long term, considerableR&D eor ts are needed to utilise the ull potential o large-scale solar systems linked todistrict heating.

The need or basic and applied research is mainly related to the development odurable and cost-eective (plastic) liners and water resistant insulation materials or

long-term (seasonal) storages. Basic and applied research is also required, relatedto the urther development o large-scale solar collectors, as well as dedicated controldevices and optimisation strategies.

Figure 23: Solar district heating plant in Graz, AT.(Source: S.O.L.I.D. Solarinstallation und Design GmbH, Austria)


60



DISTRICT HEATING

2007 2020 2030

TECHNICAL


Orientation stage or•

Compact Time-indier-ent Storage (CTIS)


materials (low cost/ high requirement) or

solar collectors andstorages is starting

R&D on absorption•

and adsorption coolingprocesses


compact storageconcepts

New materials or col-•

lectors and storages

Absorption and adsorp-•

tion cooling processes

New materials or col-•

lectors and storages

Developments in industry

Large module collectors•

or roos and ground

Building-integrated•

solar collectors

Various cooling ma-•

chines

Seasonal storage con-•

cepts by (contractors)


large module collectorsor roos and ground


building-integrated

solar collectors


cooling processes

Second generation sea-•

sonal storages concepts(contractors)

Compact storage sys-•

tems (new industry)

Next generation solar•

collectors, storages andcooling systems


Block and district heat-•

ing systems with diurnaland seasonal storageor new and existingbuildings

Solar block cooling sys-•

tems or new buildings

Solar district cooling•

Systems with compact•

storage concepts

New concepts•

61



DISTRICT HEATING

2007 2020 2030


Solar block heating•

systems with collectorson fat roos and diurnalstorages

Solar district heating•

systems with groundcollectors and diurnal

storages

Block and district heat-•

ing systems with diurnaland seasonal storagesor new and existingbuildings

Solar block cooling sys-•

tems or new buildings

Compact storage•

systems


systems o all sizes



Solar Keymark on col-•

lectorsStandards or the design•

o large systemsFull standards and•

certication or all solardistrict heating andcooling


First generation o•

systems and compo-nents with a proven lieexpectancy o 15-25yrs +

Perormance increased•

by 5-10%



Price/perormance•

reduced by another5-10%

Recycling procedures•

or all types o systems


on 20-25 yrs lietimeexpectancy

DISTRICT HEATING

2007 2020 2030

MARKET


Solar delivers only•

0.1% o total district

heatingThe market or solar in•

district heating is 1% othe total solar market

Solar delivers 1% o the•

total district heatingSolar delivers 10% o•

the total district heating


is included in 10% osolar district heatingsystems


Systems are sold turn-•

key. Training is providedby the suppliers

Solar thermal is a xed•

part o the curriculum


62



DISTRICT HEATING

2007 2020 2030

Regulatory issues

Standards: develop-•

ment towards theEU-wide acceptanceo CEN-standardsinstead o MS nationalstandards

All systems required•


CEN-standards and•

certication is required

Price / PerormanceGuaranteed Solar•

Result Contracts andother ST-ESCO solutionsare oered by only aew, peripheral marketplayers

Price/perormance•

reduced by 15-35%,depending on systemtype

Price/perormance very•

competitive comparedto traditionally alterna-tives

Financial support

Most systems are built•

with some nancialsupport

Financial support•

schemes no longerneeded or systemswithout storage or with

short-term storage.They remain necessaryor market entry tech-nologies, e.g. compactseasonal storage, dur-ing the demonstrationand market introductionstage

No nancial support is•

required

Image and awareness

Solar Thermal is now•

considered a standardoption

Market environment


starting to show interestThe technology is con-•


63



The Sun, as seen rom the surace o Earth through a camera lens.

Source: http: //de.wikipedia.org/wiki/Bild:The_sun1.jpg

(GNU Free Documentation license)

64





65




Strategic Research Agenda8



In the Deployment Roadmap above, we have considered the dierent broad areas

o application o solar thermal rom a market point o view. The Strategic Research

Agenda, however, takes an industrial and technological approach, looking mainly at

single components, such as collectors, thermal storages, cooling machines, multi-

unctional components and control systems. A more holistic approach is used in the

case o solar cooling and water treatment (desalination), as these specic applicationsimply a number o technological questions that must be solved in a coherent manner.

Each chapter, which is the result o the collective work o a number o specialists rom

industry, research and test institutes oers:

a detailed analysis and perspective on technological development;•

ormulate a specic research agenda; and•

outline a timetable or its eects.•

Solar thermal collectors are all technical systems, which convert solar radiation into heat.

Low temperature applications (< 80ºC) are by ar the most common, typically involv-

ing domestic hot water preparation and space heating. Glazed fat plate and vacuum

tube collector systems currently dominate this market. Other technologies are alsoavailable, such as unglazed collectors (or very low temperature applications, such as

swimming pool heating) and ully CPC type stationary concentrators.

At the high temperature end (> 250ºC), several high concentration technologies are

already available on the market. These are mainly used or electricity productionthrough thermal cycles (high concentration parabolic troughs, Fresnel concepts, solar

towers and paraboloids). However, this temperature range is largely outside the scope

o this report, since the ESTTP ocuses on thermal applications rather than electricit y

generation.

8 Strategic Research Agenda


8.1 Solar thermal collectors

66



Between these two temperature ranges, there is great potential or many new applica-

tions in the medium temperature range. This is relevant or buildings (due in particlar

to thermally driven cooling technologies, which require heat at temperatures up to

120ºC or single e ect systems and 160-180ºC or more ecient cycles), process heat,

including various industrial processes, as well as desalination and water treatment.

Currently, there is a lack o commercially available collectors suitable or the mediumtemperature range.

The potential evolution o existing technologies to provide collectors or the medium

temperature range includes advanced fat plate collectors, evacuated tube collectors,

stationary or quasi-stationary CPC type collectors and low concentration trackinglinear parabolic or Fresnel collectors. Some companies are now developing products

or this range, however major R,D&D e orts are still required in these areas.

Flat plate collectors dominate the European market, with more than 2 millions m²/year

installed (approximately 85% o the market). Due to the dierent application modes,

including domestic hot water, heating, preheating and combined systems, and due tovarying climatic conditions, a number o dierent collector technologies and system

approaches have been developed.

In some parts o the production process, such as selective coatings, the market has

developed to industrial large-scale production. A number o dierent materials, includ-

ing copper, aluminium and stainless steel, are applied and combined with di erent

welding technologies to achieve a highly ecient heat exchange process in the collec-tor. The materials used or the cover glass are structured or fat, low iron glass. The rst

anti-refection coatings are coming onto the market on an industrial scale, leading to

eciency improvements o around 5%.

8.1.1 Low temperature collectors

8.1.1.1 Technology status

67



The improved characteristics o collectors can lead to higher stagnation temperatures,

up to 250°C. This should not be conused with the application temperature, which

remains in the range o 80°C. Such increased stagnation temperatures require the

availability o temperature resistant back insulation materials and heat transer fuids.

Typically, water-glycol mixtures are used, but water systems are coming onto the mar-

ket with dierent rost protection technologies. Another heating option is with solar aircollectors, which are used mainly or the preheating o air in industrial buildings.

Flat-plate collectors can be installed as single modules on roos, can be manuactured

in a larger ormat or roo integration and, or acade integration, where a standard ex-

ists. Flat-plate collectors can also be installed as large modules on ground and on fatroos. Nonevacuated CPC collectors are available with very low concentration values;

they can even operate in thermo siphon systems, with higher concentration at higher

temperatures. However, the increase in concentration involves a number o unresolved

issues, including the control o stagnation temperature and the durability o materials.

Vacuum tube collectors make up roughly 10-15% o the European solar thermal mar-ket, varying rom country to country. In general, the vacuum tube collectors are more

ecient, especially or higher temperature applications. The production o vacuum tube

collectors is currently dominated by the Chinese Dewar tubes, where a metallic heat

exchanger is integrated to connect them with the conventional hot water systems. In

addition, some standard vacuum tube collectors, with metallic heat absorbers, are on

the market. New European vacuum tube collector producers are also appearing on themarket.

As or improved fat plate collectors, it must be ensured that vacuum tube collectors

can withstand stagnation temperatures. Dewar type vacuum collectors can be massproduced on a large scale at low cost. However, quality levels need to be monitored

and maintained, especially related to long-term durability. There are now some initialideas on how to integrate vacuum tubes into acades, but there is currently no standard

technology available. Vacuum tubes could also be combined with low concentration

optics (CPC type or other), creating a new amily o collectors, which might be very

ecient at temperatures ranging rom 100ºC to 180ºC.

At present, low temperature collectors are widely used. There are also many otherhigh quality products on the market, which ollow dierent approaches, depending on

climatic conditions and applications.

However, in view o the anticipated market development, a number o technological

challenges are arising. Some o the key issues include cost reduction, higher quality,aesthetics and building integration.

With regard to cost reduction, the basic trade-o between cost and quality (perorm-

ance, durability, recyclability and aesthetics) need to be considered. The bulk o the

European market has evolved towards higher quality products and systems, but thishas not been the case elsewhere (or example, in China, which accounts or more than

two thirds o global sales). Looking at the European market, there is ample potential

to develop cheaper products, which may be less durable and eective, but which are

cheaper and can be easily replaced. This may lead to a di erent approach, whichcould be advantageous i lower perormance is compensated by lower costs and thus

a aster uptake o solar thermal energy use.

8.1.1.2 Potential and challenges or technological development


68



Building integration is relevant or both new and existing buildings. It includes issues

such as the:

inclusion o solar collectors in pre-abricated roos, awnings and acades; and•

urther development o collectors conceived or ver tical uses (acades), including•

large area acade-integrated collectors, which can be combined with so-called

active walls or with photovoltaic modules.

Higher levels o building integration require new rounds o RD&D e orts, in close

interaction with architects, construction companies and manuacturers o building

envelopes.

A related issue is collector size, which is traditionally relatively small (around 2m²).

However, there is a recent trend towards larger collector sizes, implying a di erent

set o conditions or collector design, manuacturing, logistics and installation. In this

area, there is signicant potential or technological development. Taking into account

the projected rapid increase in market size, the recycling potential o materials used inthe solar collectors will be a major issue. The liecycle assessment o the whole solar

thermal system, taking into account the energy uels and the materials they replace,

will also be crucial. And the role o new approaches, such as the active wall concept

that heats and cools the room behind it, are very promising and should be developed.

For all issues mentioned in this chapter, specic RD&D at tention should be given to air

and vacuum tube collectors. Although air collectors have great potential, particularly

or applications such as space heating, ventilation and space cooling through ventila-

tion, they are less developed than liquid based collectors. For vacuum tube collectors,the potential or ur ther development lies mainly in improved building integration. This

includes easier tube replacement in case o ailure, resistance to stagnation, possiblethermal improvements and longevity.

Clearly, a major issue is the automation o manuacturing processes, particularly or

collector construction, where there still is great potential or increased productivity.

Major eorts are needed in the ollowing areas:

More ecient ways to use conventional collector materials (metals, glass, insula-•

tion), especially with a view to developing multiunctional building components,

which also act as an element o the building envelope and a solar collector.

Evolution in the optical properties o collector components. In particular, a more•

systematic use o optical lms to enhance heat /light transmission in glass covers

and reduce this transmission during excessive exposure; and the use o colours inabsorbers or covers to achieve more fexible integration concepts.

Alternative materials or collector production: the use o polymers or plastics, the•

coating o absorbers optimised to resist stagnation temperatures and new materi-als to tackle deterioration resulting rom UV exposure.

Improvement in the recycling potential o collector components and materials in•

view o liecycle cost reduction, and overall sustainability o materials.

69



Special topics will include issues such as:

The control o solar energy delivered by entire acades, in particular the aspects•

related to ault detection and the consequences o stagnation temperatures when

a prolonged no-load situation coincides with peak solar radiation;

New component testing and evaluation methods; and•

A dedicated concept or the automation o manuacturing processes and assem-•

bly techniques.

Some process heat applications can be met with temperatures delivered by “ordinary”low-temperature collectors, namely rom 30 to 80°C. However, the bulk o the demand

or industrial process heat requires temperatures rom 80°C up to 250°C.

Process heat collectors are a new application eld or solar thermal heat collectors.

Typically, these types o systems require a strong capacity (and thereore large collec-

tor areas), low costs, and high reliability and quality.

While low temperature and high temperature collectors are oered in a dynamically

growing market, process heat collectors are at a very early stage o development and

there are no products available on an industrial scale.

The technological approaches or process heat collectors can be grouped according tothe concentration ratio or the tracking mode. Optical concentration is a way to achieve

higher operation temperatures, by reducing the absorber area with respect to the ap-

erture area. The drawback is that concentration reduces the angular acceptance o the

aperture area, which means the collector’s orientation needs to be adjusted towards

the sun. This adjustment is usually seasonal or low concentration ratios, while morerequent adjustments are required or higher concentration ratios. Tracking involves

additional mechanical structures with moving parts, which imply additional costs and

maintenance needs.

In addition to these “concentrating” collectors, improved fat collectors with double and

triple glazing are currently being developed, which might be interesting or processheat in the range o up to 120°C.

8.1.2 Process heat (medium temperature) collectors

8.1.2.1 Technology status


70



Increasing the temperature o the heat delivered, while keeping the collector eciency

above 50% is quite a challenge, and requires major RD&D eort s, rom industry and

the academic world. In this respect, eorts are already underway, but there is still a

long way to go.

Initial RD&D eor ts will be directed towards the:

control o heat loss; and•

maximisation o energy collection.•

The control o heat loss will be addressed by managing convection through the use o:

double glazing;•

honeycomb transparent insulation materials;•

single transparent lms; and•

by applying heavy molecules to create an iner t inner atmosphere.•

Work in these areas will lead to so-called advanced fat plate collectors. Heat loss con-

trol will also be addressed by the introduction o concentrators, with or without track-

ing. The maximisation o energy collection will encourage the use o high perormanceoptics, such as CPC in single or double stage concentrating s teps. Evacuated tubular

collectors with concentrators could be useul in tackling both these issues.

For process heat collectors, research into materials is crucial. Long-term resistance o

components at ever higher temperatures must be improved and better materials are

needed to produce the concentrating optics. These developments will also require acorresponding evolution in manuacturing techniques, systems testing and cer tication

and installation.

For most industrial processes, continuity o operation must be guaranteed. Managers

o industrial acilities are, thereore, sceptical about any intervention that could poten-tially cause interruptions to the heat supply system. The act that there are only a ew

working solar thermal process heat systems means that trust in these systems has not

been built up, potential users are not attracted and costs are increased or individual

projects.

At the same time, industrial heat users are oten able to purchase oil or gas at muchbetter rates than private households, increasing the barriers to solar uel savers.

8.1.2.2 Potential and challenges or technological development

8.1.2.3 Non-technical challenges or solar process heat collectors

71



In order to reduce these non-technical barriers to the wider deployment o solar process

heat, it is important to:

establish strong and ocused nancial incentives, leading to a signicant number•

o demonstration projects, possibly with the goal o creating critical mass in a

specic industrial and/or geographical sector;

adjust existing quality norms and certication procedures or low temperature col-•

lectors, making them applicable to process heat collectors; and

promote solar thermal energy service companies (ST-ESCOs), oering their serv-•

ices to the industrial sector.

The undamental challenge here is the development o a new generation o process

heat collectors, raising the temperature, eciency and perormance o current lowtemperature collectors.

The main basic research topics arise in the eld o materials research.

Functional suraces (such as anti-refective or low-e coatings, sel-cleaning sur-•

aces and anti-corrosive coatings)

Highly refective, precise and weather resistant lightweight refectors•

Improved selective absorbers (or example, long-term stability in aggressive•

climates, such as salt-water droplets rom the sea)

Cheaper glass with high solar transmittance and exchangeable optical properties•

Heat transer fuids with higher temperature stability (above 160 °C)•

Temperature-stable and inexpensive thermal insulation (or example, vacuum•

insulation)

New design concentrators, avouring roo mounting and low maintenance needs•

New heat transer media, withstanding reezing and high operating temperatures•

New concepts or system integration and overheating protection•

Depending on the price evolution o current raw materials, such as copper, aluminiumand oil-based plastics, substitution materials may need to be developed. New concepts

like PV-thermal collectors will require specic basic developments, which are not cur-

rently available.

8.1.3 R&D agenda


72



The main applied research topics are:

New manuacturing techniques or the large-scale production o medium tem-•

perature collectors and components.

Stagnation-proo collectors and ways to prevent or mitigate the diculties associ-•

ated with stagnation. This is particularly relevant or industrial processes that do

not run continuously.

Reliable methods to remove air rom the collector circuit, in order to achieve an•

even fow distribution and to slow down the aging o the heat transer fuid.

New testing techniques geared towards accelerated aging tests o solar system•

collectors and components, covering specicities arising rom the use o collec-

tors in acades and maritime ambience.Large systems control and management, reducing maintenance costs without•

lowering perormance.

Simple concepts or quasi–stationary concentrators (tilt adjusted).•

Integration with conventional heat sources or into conventional systems.•

Integration into building suraces (or example, in combination with shading•

devices).

Component durability without lowering perormance (light and cheap refecting•

suraces and conventional selective absorbers).

Precise, robust and cost-eective tracking devices (adjusted according to the•

required degree o accuracy).

Solar air process heat collectors.•

The main topics or development are:

Develop cheap and reliable collectors based on new materials, which are easy to•

integrate into various roos and acades.

Develop practical ways to integrate conventional metal collectors onto metal•

acades and roos.

Develop collectors that can be connected with a heat pump (i.e. condensation•

inside the collector must not be a problem)

Improve heat transer in the collector and heat exchanger•

Develop cheap, energy-ecient pumps•

Develop connectors that acilitate the quick and easy installation o collectors.•

Develop evacuated tube collectors with a better price/perormance ratio (soda-•

lime glass and anti-refective coatings).

Develop low concentration stationary or quasi-stationary collectors or higher•

temperature applications in buildings, which can be combined with evacuated

tubular collectors.

Develop PV-thermal hybrid collectors that save installation costs and increase•

total conversion eciency, compared with side-by-side systems.

Air collectors with improved heat transer.•

Develop cheap sensors and electronics or ault detection and identication.•

73



Timetable specics or low temperature collectors:

Short term

2008 – 2012

Medium term

2012 – 2020

Long term

2020 – 2030

and beyond

Industry

manuacturing

aspects

Absorber•

production

technologies

Combining•

collectors andbuilding

components

Automatic•

production o

collectors as

building

components

Full integration•

o new solutions

in building

codes and

practices

Applied/advanced

technology aspects

Improved sensor•

technology

The use o•

colour in solar

collectors

Test procedures•

or accelerated

lie time tests

Air collectors•

providing heat-ing and cooling

Window-like•

technology or

collectors

PV-T collector•

Hybrid PV-T col-•

lector with stor-

age or acadeintegration

Basic researchundamentals

Heat transer•

fuids

Vacuum•

insulation

Functional coat-•

ings

New materials•

Polymer•

absorbers,

boxes, and

covers

Combined•

collector-storage

systems

Switchable coat-•

ings

“Invisible” col-•

lector is a practi-cal reality

8.1.4 Timetable


74



Time table specics or process heat (medium-temperature) collectors:

Short term

2008 – 2012

Medium term

2012 – 2020

Long term

2020 – 2030

and beyond

Industry manuac-

turing aspects

Development goal:

Process heat•

collector:

600 € /kWth

Manuacture•

rst pilot plants

based on the

prototype collec-tors developed

in recent years

Installation o•

subsidised pilot

projects on the

basis o existing

technologies

Discuss integra-•

tion o processheat collec-

tors in existingstandards

Development goal:

Process heat•

collector:

400 € /kWth

First industrial-•

scale manuac-

turing o process

heat collectors

Gradual reduc-•

tion in subsidiesor demonstra-

tion projects

Implementation•

o standards

in a European

and national

ramework

Development goal:

Process heat•

collector:

300 € /W th

Fully industrial-•

scale manuac-

turing o process

heat collectors

Reach baseline•

o subsidies or alarge number o

industrial pro-

cess heat

projects in

all European

countries

Implementation•o standards that

cover all avail-able collector

technologies

Applied/advanced

technology aspects

Development•

o perormance

test procedures

or process heatcollectors

Improved and•

cost eectivetracking

systems

Integration o•

process heat

collectors into

industrial

buildings

Standardised•

system designs

Investigation•

into process

integration

Perormance•

test procedures

implemented

Second genera-•

tion o process

heat collectors

at signicantlylower cost

and increasedperormance,

due to the use o

new materials

Full integration•

o process heat

collectors into

industrial build-

ing structures

Standardised•

solar heat inte-gration

75



Short term 2008 – 2012

Medium term 2012 – 2020

Long term 2020 – 2030

and beyond

Basic research

undamentals

New optical•

designs

New materials•

or:- structures- refectors- receivers

- heat transermedia

Lie-cycle Cost•

Assessment LCA

Reliability and•

durability omaterials

Higher perorm-•

ance materials

Introduction o•

new materials

New concept•

testing

Heat storage increases the use that can be made o the solar resource by allowing heatto be ‘consumed’ when there is demand or it, rather that at the time when it is pro-

duced. Storing solar heat or one or two weeks, is a common practice, with acceptable

costs and heat losses. Dierent solutions or heat storage on a timescale o seasons

(several weeks or months) have allowed solar heat accumulated over the summer to

be used during the winter months. However, these technologies are still in their inancy.

Only when seasonal heat storage is widely available at low costs will it be possible toachieve the ESTTP’s vision o 100% solar space heating as standard in new buildings.

Some o the key parameters to be considered or thermal s torage systems are: cost,

capacity, charge and discharge power, space taken up by the heat store, time between

charging and discharging, transportability, saety, and integratability into buildingsystems.

Short-term buer storage systems show short reaction times, and must deliver high

power with small capacities. “Medium term” stores dene stores rom one day upwards.

Low storage capacities are measured in the kWh scale, while large ones are in MWh.

The size o the store depends on the specic heat capacity o the heat storing medium

(usually water), the heat capacity o which is relatively low: large volumes are needed

to store relatively small amounts o heat. This is a problem because space inside (or

below) buildings is expensive. For example, in order or solar energy to cover the ull

space heating and hot tap water needs o a well-insulated house in Central Europe, a

typical water heat storage o about 30m3 at 85 °C would be required, equivalent to10% o a typical house’s usable space! The ratio o store size to building size is better

in larger buildings with many residential units.

8.2 Thermal storage


76



The large size o season-scale stores makes it dicult to use solar heat in winter. It is

also dicult to integrate such systems into existing buildings. Thereore, developing

new, compact season-scale heat storage technologies is crucial or the commer-

cialization o solar thermal systems capable o covering 100% o space heating and

domestic hot water demand.

Another important parameter is the required storage temperature. Low temperature

stores are used in buildings to stop room temperatures alling below 20-24 degrees.

The termperature o the storage medium is less than 100 °C. Medium temperature

stores store heat or industrial applications at temperatures exceeding 100°C, where

non-pressurised liquid water cannot be used as a storage medium. The upper tempera-ture limit corresponds to the temperature limit dened or low or intermediate concen-

trating solar collectors.

Heat can be stored at low temperatures or periods up to six months. The size and

capacity o the storage technology is not only determined by the storage period, but

also by the building’s demand or heat. For example, there is a signicant dierencein heating demand between an oce building in the Mediterranean area and a one-

amily house in Denmark.

The theme o ”thermal storage” also includes systems that store cold. It can be wise to

include cold storage in thermally-driven rerigeration systems (see later).

Four main types o thermal energy

storage technologies can be distin-

guished: sensible, latent, sorption

and thermochemical heat storage2.

Sensible heat storage systems use

the heat capacity o a material. When

heat is stored, the temperature o thematerial increases. The vast majority

o systems on the market is o this type

and use water or heat storage. Water

heat stores cover a very broad range

o capacities, rom several hundredlitres to tens o thousands o cubic

metres. Medium temperature heat is

stored in a single-phase storage mate-

rial. In single-phase materials, the state o charge corresponds to the temperature o

the material concerned. Examples o materials are concrete, molten salt, or pressurisedliquid water. Storage systems using molten salt at temperatures between 300°C-400°C

were demonstrated in solar thermal systems in 2008.

8.2.1 Technology status

2 Thermal energy storage or solar and low energy buildings. State o the art by the IEA Solar Heating andCooling Task 32. June 2005, editor Jean-Christophe Hadorn, ISBN: 84-8409-877-X.

Figure 24: Water lled heat storages are cur-rently the most common sensible heat storage

systems. (Source: Vaillant, Germany)

77



In latent heat storage systems,

thermal energy is stored during thephase- change, either melting or

evaporation, o a material. Depending

on the temperature range, this type

o storage is more compact than heat

storage in water. Most o the currentlyused latent heat storage technologies

or low temperatures are or storing

heat in building structures to improve

thermal perormance, or in cold stor-

age systems. For medium temperature

storage, materials used or storage arenitrate salts. Pilot storage units in the

100 kW range are currently operated

using solar steam.

In sorption heat storage systems, heat is stored in materials using water vapour up-taken by a sorption material. The material can be either a solid (adsorption) or a liquid

(absorption). These technologies are still largely in the development phase, but some

are on the market. In principle, sorption heat storage densities can be more than our

times higher than sensible heat storage in water.

In thermochemical heat storage systems, the heat is stored in an endothermic chemi-

cal reaction. Some chemicals store heat 20 times more densely than water, but more

usually, the storage densities are 8-10 times higher. Few thermochemical storage

systems have been demonstrated. The materials currently under investigation are all

salts that can exist in anhydrous and hydrated orm. Thermochemical systems can

compactly store low and medium temperature heat.

Figure 25: An experimental latent heat storage

with macro encapsulated PCM (paran).(Source: Ciril Arkar, University o Ljubljana,

Slovenia)

Figure 26: The principle o thermochemicalheat storage: heat is used to separate a

chemical compound into its component parts.

The components can then be stored or longperiods with practically no heat loss. When the

components are reunited, a chemical reactionoccurs and heat is produced.(Source: ECN, The Netherlands)


78



In order to achieve a larger solar raction in housing stock, a new generation o

thermal energy stores are needed. These stores must be compact, cost eective, sae,

clean and easy to handle. To meet these requirements, new materials and technologies

must be developed.

At present, the research groups working on thermal energy storage are spread aroundEurope, small, and insuciently aware o each other’s work. For decades, the main

potential beneciaries o thermal storage technology, which include the cogeneration

and district heating sectors, have not unded the basic research needed to advance this

technology. Nor have public bodies.

This might soon change. The creation o the European Solar Thermal Technology Plat-

orm, which is dening thermal storage as an R&D priority, aims to secure public and

private spending on this research.

Innovation in compact thermal energy storage would be boosted signicantly i a

strategy were dened and executed between research centers and industry or thistechnology’s short-, medium-, and long-term R&D.

A network o experts and companies interested in thermal energy storage should be

built up. Sharing inormation, expertise and acilities e ectively is a precondition orrapid progress in research, development and innovation. Public R&D unds should beearmarked or thermal storage at national and European level.

Basic research

Basic research in new materials to store much thermal energy in little space is essen-tial, with thermochemical systems the ront-running technology or the most compact

systems. The materials in existing systems, based on PCMs and sorption should be

improved or replaced with better materials.

The most important research topics are:

Material development

Improvement o compact storage materials, such as zeolites, Metal Organic•

Framework (MOF), silica gels, hydration reaction thermochemical materials and

other thermochemical materials. The development should be aimed at improving

thermo-physical properties, including storage capacity, heat transer, structuralintegrity and hydrodynamic behaviour.

8.2.2 Potential and challenges or technological development

8.2.3 Research agenda

79



Better understanding o the relation between structure, composition and thermal•

storage characteristics o these materials;Improved techniques or the synthesis and production o compact storage materials;•

Characterisation and standard tests or materials;•

Numerical models or molecular and crystalline interactions;•

Multi-scale numerical modeling: coupling o models on a micro and meso/macro-scale.•

Materials with high ability to insulate, including vacuum insulation and aerogels;•

Improved phase change materials (PCM) to achieve higher latent heat values•

at the appropriate temperature levels and gain a better understanding o how to

master sub-cooling and the phase separation. Improve the long-term stability o

PCMs.

Understand the eec ts o combining materials rom dierent classes, or combin-•

ing a thermal storage material with a carrier material. Such as, silica gel andzeolite combinations; salt hydrate in zeolites; silica gels or zeolites in metal

oams; and the use o carbon lattices.

Combinations o active materials with a liquid carrier: suspensions o micro-•

encapsulated or micro-coated phase change materials, controlled crystallisation,

emulsions o active materials, ionic liquids and the development o additives.

Combined PCMs (organic and inorganic) in order to eliminate certain undesirable•

characteristics o individual PCMs;

Materials and techniques or encapsulation and coating o phase change materi-•

als and materials that absorb heat by changing their chemistry;

Suspension and emulsion techniques or compact thermal energy storage materials.•

Numerical models in order to understand the encapsulation process, material•

choices and the emulsion techniques.

Laboratory tests and simulations to improve the interaction between multiphase•

fow and solid walls, thus increasing the heat transer rate;

Figure 27: Sample o magnesium sulphatepowder - one o the thermochemical materials

under investigation.

(Source: ECN, The Netherlands)


80



Chemical technology

Thermochemical reactor technology or heat production and storage, using heat•

rom distributed systems or solar collectors

Two-phase reactors with optimised heat and mass t ranser•

Micro-reactor systems or heat storage in distributed systems or in novel solar•

thermochemical collectors: heat and mass transer on the micro-scale

Reaction catalysis: understanding and developing the eect o catalysts on ther-•

mochemical processes

Membrane technology: development o membranes or the selective transer o•

reactants

Applied research

PCM macro-encapsulation techniques that take into account material compatibil-•

ity, saety and durability, with the aim o integrating PCMs into building construc-

tion and components

Transport o powder, suspensions and emulsions or both PCM and thermochemi-•

cal materials within systems and components

Fast and secure connection o pipes and wires•

Low-cost sensors and communications technology or heat fow, fuid fow, tem-•

perature, pressure and compositionFlexible volume tank systems; fexible walls or fexible diaphragms•

Further development o a range o reactors or thermochemical heat s torage and•

or sorption thermal storage systems. These include hydrate powder, membrane

and suspension reactors

Study and optimisation o combined heat and mass transport inside a reactor•

Sorption material production technology development, with special attention to•

the combined production o sorption material and heat transer suraces

Emulsion techniques or paran•

Measurement technologies to identiy charging status o latent heat storage•

systems

Optimisation o hydraulics in advanced water stores, reduction o mixing and•

increased stratication

Coatings or tank and pipe suraces•

Technologies to mix phase change materials with or into building materials•

Optimised or intelligent hydraulics and/or air fow schemes and control systems•

or the use o thermal storage in heating systems

81



Demonstration

It is necessary to demonstrate both the unctioning o newly developed materials or

methods, and to prove new concepts on the laboratory scale.

This should be ollowed by demonstrating the technology in a complete system, to

ascertain the extent to which they improve on state-o-the ar t technology (i.e. what

solar raction they achieve). Several technology lines should be ollowed in parallel,

including advanced water, PCM, sorption and thermochemical. The development o

other components and auxiliary equipment should proceed in parallel. The durabil-ity o near commercial solutions, including their technical components, must also be

demonstrated, in order to estimate their long-term perormance. It is also important to

demonstrate systems that include heat storage or short and long periods.

In medium temperature heat storage, the ollowing should be demonstrated:

employing thermal storage to reduce the start-up time;•

using storage to prevent system overheating;•

dynamic solutions or reaction time and peak-power o heat storage; and•

long-term perormance o storage units.•

Short term

2008 – 2012

Medium term

2012 – 2020

Long term

2020 – 2030

and beyond

Industry

manuacturing

aspects

Advanced water•

heat storages

PCMs•

Medium tem-•perature storagecost

optimisation•

o design andnorms

denition o•

standards

Improved sorp-•

tion systems

First systems•

with advanced

heat storage

materials

Compact heat•

storage system

technology

Commercial•

applications o

low and medium

temperature

storage tech-

nologies

8.2.4 Timetable


82



Applied/advancedtechnology aspects

Improved•

production

technologies or

sorption materi-

als and PCMs

Novel storage•

geometries and

auxiliary materi-

als

Control inter-•

aces

First stor-• age systems

demonstrated

to replace ossiluelled acilities

Storage systems•

to reduce start-up time and

compensate or

cloud transients

Production•

technologiesor advanced

materials and

reactors

New medium•

temperature

storage materi-

als and concepts

to be demon-strated

Micro reactor•

devices

Synthetic materi-•

als rom materi-als engineering.

New ther-•

mochemicalsystems

Medium tem-•

perature storagetechnology to

enable solaronly operation

o solar thermal

power

Basic research

undamentals

Advanced mate-•

rials or compact

thermal storage

Reactor tech-•nologies

Development•

o theoretical

and numerical

methods

Reactor heat•

and masstranser

Micro reactor•

technologies

Numerical meth-•

ods or materialsengineering

Reaction cataly-•

sis, membrane

technology

Second genera-•

tion o medium

temperature

storage materi-als

Most cooling and rerigeration systems worldwide are powered by electricity. Thermally

driven cooling technologies are set to play a key role in the ecient conversion oenergy in the eld o building air-conditioning and rerigeration. Today, these technolo-

gies are used largely in combination with waste heat, district heat or co-generation

units. One o the main advantages o such sytems is that thermally driven cooling

cycles can be run with solar thermal energy, thus producing solar air-conditioning and

8.3 Solar thermally driven cooling and rerigeration

83



rerigeration. Over the last two decades, most installations have been publicly unded,

in the ramework o research demonstration programmes. Only very recently, the start

o market development has been observed in the residential sector in Mediterranean

countries, particularly in Spain. There is substantial potential to support this develop-

ment with urther R&D work.

Industrial rerigeration

There is a large and slowly growing market or industrial rerigeration, especially or

ood or medicines. Rerigeration units will deliver temperatures in the range -30°C to20°C. The output o most units is in the range o 100 kW to several MWs.

Conventional systems are operated by large, electrically driven, vapour compression

rerigeration machines, which supply cold air to a distribution network. The perorm-

ance o a rerigeration cycle is usually described by the coecient o perormance

(COP), dened as the benet o the cycle (amount o heat removed or cooling capac-ity), divided by the total energy (or power) input required to operate the cycle. The COP

o electrically driven cooling machines ranges rom 3 to 6, and is largely a unction

o the required output temperature. Usually, large cooling towers are employed to dis-

sipate condenser heat.

Several industrial installations use waste process heat to operate thermally-driven cool-ing equipment, which is competitive with vapour compression technology in areas with

an unstable electricity supply. Thermally-driven cooling systems applied or industrial

rerigeration always use closed thermodynamic cycles, which produce cold air, which

is transerred by a liquid (or solid/liquid, such as ice slurries) heat-transer medium. Atpresent, solar thermally-driven industrial rerigeration includes systems employing roo-or ground-mounted low- and medium-temperature solar collectors. These systems can

be coupled with hot or cold stores, depending on the application. Only a small number

o these applications have been studied and a ew new systems are in operation in the

southern Mediterranean.

Currently, solar thermally-driven systems nd it hard to compete with conventional,electrically- driven rerigeration equipment. The high capital cost o solar rerigeration

is particular actor preventing wider market uptake. On the other hand, the rising price

o electricity and the number o successul solar industrial rerigeration demonstration

projects have made such systems more attractive. In this eld, there still is a great

potential to develop economies o scale in manuacturing, oering thus excellent

medium-term prospects.

Air-conditioning o buildings

The demand or cooling in buildings is rising across the world and notably in southern

Europe, in both the residential and tertiary sectors. This has created a massive increasein peak electricity demand, putting heavy demands on power supply inrastructure and

generation capacity, increasing the risk o blackouts and o damaging the environ-

ment. Alternatives to electrical cooling need to be developed rapidly. While demand-

side management is crucial, on the supply side solar thermal is the best medium-term

solution.


84



Around 250 solar air-conditioning systems were installed in Europe by 2007, with

an exponential increase o activity in the last two years. Solar collectors or the air-

conditioning o buildings are generally also used or other applications, such as space

heating and domestic hot water production. This increases energy savings and thus

the productivity o the investment. The systems in operation range rom small units or

single-amily houses to large units or the air-conditioning o actory buildings.

Conventional air-conditioning is based on vapour compression cycles that consume

signicant amounts o electricity to drive the compressor. In the building sector, the

market is dominated by small single-split systems (or a single room) or multi-split

systems or a fat or a foor level. Typical COPs or small split systems are about 2.5 to3. In larger commercial buildings, there oten are cooling networks operated by large

centralised water chillers. These systems can achieve much higher COP-values o up to

5-6, in particular when they use a wet cooling tower to reject the waste heat.

Although the basic principles remain the same, there are three main dierences in thetechnologies used or air-conditioning in buildings and industrial rerigeration:

1. Air-condi tioning o buildings in summer can include both cooling and, depending

on the outdoor humidity and internal latent loads, dehumidication. So, both ther-

modynamic machines and so-called open cycles (also called desiccant cooling

systems) can be applied. In open cycles, air passing through a thermally-drivenair handling unit is brought to the correct temperature and humidity. The heat can

come rom solar collectors.

2. Depending on the indoor systems, the temperature o output air should usuallyrange rom 6°C to 16°C. Temperatures below 6°C are not necessary unless icestorage is required. Output termperatures in this range can be produced by solar

thermal systems.

3. Systems or air-conditioning come in many sizes, rom small water chillers, with a

capacity o ew kW or single-amily houses, to centralised systems or air-condi-

tioning large buildings, which can be in the range o several MW capacity. Smallthermally-driven water chillers came on the market only very recently

Solar assisted air-conditioning o buildings currently requires low- and medium-tem-

perature solar collectors, which are usually roo mounted. For large buildings, ground

mounted collector systems are also used. There are two major types o cooling cycles:

Open cooling cycles, in direct contact with environmental air. They use a sorptive•

component, able to dehumidiy air. This increases the potential or using evapora-

tive cooling. Heat is required to remove the water vapour bond in the sorption

matrix.

Closed cycle machines, employing a rerigerant that undergoes a closed thermo-•

dynamic process. It is thereby able to take up heat at a low temperature level (the

useul cooling eect) that is then released at a medium temperature level (heatusually rejected into air). The process is driven by the dierence in temperature

between the input heat rom the collectors or heat store and the temperature o the

heat sink.

85



Open cooling cycles (or desiccant cooling systems) as discussed above, are mainly o

interest or the air-conditioning o buildings. They can use solid or liquid sorption.

The central component o any open solar-assisted cooling system is the dehumidica-

tion unit. In most systems using solid sorption, this dehumidication unit is a desiccant

wheel, which is available rom several suppliers or dierent air volume fows. Various

sorption materials can be employed, such as silica gel or lithium chloride. All othersystem components are to be ound in standard air-conditioning applications with an

air handling unit and include the heat recovery units, heat exchangers and humidiers.

The heat required or the regeneration o the sorption wheel can be provided at low

temperatures (in the range o 45-90°C), which suits many solar collectors on themarket. Other types o desiccant dehumidiers using solid sorption exist. These have

some thermodynamic advantages and can lead to higher eciency, but place higher

demands on the material and the equipment. There is potential or urther R&D work

here.

Liquid sorption techniques have successully been demonstrated. The input air isdehumidied when it comes into contact with a salt solution, such as water/lithium

chloride. The diluted solution is re-concentrated using low temperature heat that can

be provided by solar collectors. The advantage o liquid sorption is the capacity o the

concentrated and diluted salt solution to store energy, without heat loss. This enables

high density energy storage. The temperature required or regeneration is comparable

to that required or solid sorption, and is thus perectly compatible with solar collectors.

Closed heat driven cooling cycles have been known or many years. They are usually

used or large capacities, rom 100 kW upwards. The physical principle used in mostsystems is based on the sorption phenomena. Two technologies are established toproduce thermally driven low and medium temperature rerigeration: adsorption and

absorption.

Absorption technologies cover the overwhelming majority o the global thermally

driven cooling market. The main advantage o absorption cycles is their higher COPvalues, which range rom 0.6–0.8, or single stage machines, and 0.9 –1.3 or double

stage technology. Typical heat supply temperatures are 80–95°C and 130–160°C

respectively. The absorption pair in use is either lithium bromide and water or

ammonia and water. For lithium bromide and water cycles, the evaporator tempera-

ture is limited to 4°C and the condenser temperature is below 35°C. The condenser

temperature means that a costly and high water consuming wet cooling tower is oten

required. Ammonia and water cycles allow or designs that can reach evaporatortemperatures o below 0°C, and heat rejection temperatures o up to 50°C. Thereore,

they can be used or deep reezing applications, using dry air-cooled condensers or

heat dissipation.

Adsorption rerigeration cycles using, or instance, silica gel and water as the adsorp-

tion pair, can be driven by low temperature heat sources down to 55°C, producing

temperatures down to 5°C. This kind o system achieves COP values o 0.6-0.7. Today,

the nancial viability o adsorption systems is limited, due to the ar higher production

costs compared to absorption systems.



86



A number o thermally-driven cooling systems have been built employing closed

thermally-driven cooling cycles, using solar thermal energy as the main energy source.

These systems oten cater or large cooling capacities up to several hundred kW.

In the last 5-8 years, a number o systems have been developed in the small capacity

range, below 100 kW and in particular below 20 kW down to 4.5 kW. These smallsystems are single-eect machines o di erent types, used mainly or residential build-

ings and small commercial applications.

While open cooling cycles are generally applied or air-conditioning in buildings,

closed heat-driven cooling cycles can be used or both air-conditioning and industrialrerigeration.

Other cycles - Other options or the conversion o solar energy into useul cooling

besides sorption-based cycles also exist. In an ejector cycle, heat is transormed into

kinetic energy o a vapour jet, which enables the rerigerant to evaporate. In a solarmechanical rerigeration cycle, a conventional vapour compression system is driven

by mechanical power that is produced with a solar driven heat power (or example,

Rankine) cycle, in which a fuid is vaporised at an elevated pressure by heat exchange

with a fuid heated by solar collectors. Last but not least, elec tricity generated in a

photovoltaic array can be used to operate ordinary vapour compression machines.

Increased cost-perormance• : When compared to mechanical (i.e. electrical)

vapour compression, heat driven cooling is still new and relatively unexplored

technology. There is signicant potential or lowering costs and/or increasing per-

ormance through technological improvements in basic materials, to componentdesign and systems technology.

Lack o practical experience and specifc know-how• : A major barrier to the

widespread implementation o solar air-conditioning and rerigeration systems isthe lack o awareness o and experience in these technologies. Too ew people are

knowledgeable both o solar thermal and air conditioning in buildings. The decit

in solar thermal knowledge is par ticularly marked among specialists in industrial

rerigeration.

High investment cost• : Solar driven air-conditioning and rerigeration systems

have a high capital cost because o the many components involved in the system:

the cooling equipment, the solar collectors and the heat storage appliances. At

present, these systems are not competitive with conventional electrically-drivencooling systems. This is especially the case o commercial applications, where a

short return on investment is expected.

Lack o technology• : Most o the thermally-driven cooling components on the mar-ket now have not been designed to operate with solar energy. The designs must

be adapted to cope with varying input temperatures and input powers.

Ecient heat dissipation systems, which are easy to maintain and operate at low

temperatures, are not yet available. New components need to be developed in

both these areas.

8.3.2 Challenges and potential or technological development

87



Building integration• : At present, systems are added to a building ater it has been

built. In uture, systems will increasingly be incorporated in new buildings as they

are being built. Solar collector and heat sinks and heat stores could be integrated

into buildings (the latter, or example, through phase change material in the build-

ing structure).

Use o solar cooling in industrial processes hindered by over-designed systems:•

The cold supply rom most equipment in industrial processes is provided at

temperatures ar below the levels that are actually required by the process. As aconsequence, the potential or integration o solar driven rerigeration systems is

signicantly reduced, and in many cases excluded.

Lack o design guidelines and design tools• : There are only a ew people andresearch institutes with experience in solar cooling or buildings; and even ewer

with experience in solar rerigeration or industrial purposes. There is also a lack

o design guidelines and tools specically developed or solar cooling systems or

particular applications. Stagnation-proo collector designs need to be developed.

With these tools, costs could be brought down. These elements strongly contribute

to the currently high cost o solar cooling.

Awareness• : particularly a problem or solar rerigeration.

This section only covers research activities that specically relate to thermally driven

cooling. Research activities related to the components o solar thermal systems in

general, such as solar collectors and thermal storage, are only mentioned i they needspecic attention in relation to thermally driven cooling.

Basic research with the long-term aim o optimising thermally-driven cooling cycles is

required. Basic research is needed to:

achieve a higher co-ecient o per ormance (COP-values)•

make machines more compact•

enable machines to operate at lower driving temperatures•

Research on new sorption materials, new coatings o sorption materials on heatexchanger suraces, new heat and mass transer concepts and the design o new ther-

modynamic cycles will be needed. It will also be needed or cold stores, which coulduse phase change materials and thermo-chemical reactions.

8.3.3 R&D needed to achieve the goals


88



Basic research topics include:

The development o new, highly porous sorption materials, in particular using•

adsorption chemistry. Many materials have not yet been ully investigated or heat

transormation applications. Ionic liquids may also be candidates or new liquid

sorption working pairs.

Sorptive material coatings on dierent metal substrates or optimised heat and•

mass transer

Micro-fuid systems or compact, highly ecient heat exchangers in the sorption•

and desorption regimes

New sorption heat exchanger matrices, such as metal oams•

Nano-coated suraces in heat exchangers or reduced riction losses during fuid fow•

New materials or cold storage at dierent temperature levels or high storage•

density

New cycles (high temperature lit; double, triple stage and novel open sorption)•

with optimised internal heat recovery or high COP-values

Perormance analysis tools, such as exergy analysis, lie cycle analysis and com-•

parison methodologies to assess new concepts

Advanced simulation tools or systems modelling at dierent scales, starting rom•

the molecular scale (sorption phenomena) up to the system scale

Applied research

The main ocus o applied research is to develop machines or apparatus based on new

approaches. Applied research also includes the development o test methods or the

standardisation o thermally driven cooling cycles.

Applied research topics include:

Integration o the new heat exchanger concepts, developed in undamental•

research, into a machine concept

Advanced machines based on the new thermodynamic cycles, including hybrid•

sorption-compression systems or operation with heat and electricity alternatively

Highly compact machines o a capacity to cool a single room; these machines•

could be adapted or use in road vehicles Adjustment o machines or solar operation, i.e. under variable temperature and•

power conditions (highly fexible cycles)

Advanced ejector cycles using dierent working pairs adjusted to dierent ap-•

plications

• Advancedopencyclesusingliquidsorptionmaterialswithahighstoragedensity

89



• Cooledopensolidsorptivecycleswithahighdehumidicationpotentialforwarm

and humid climates

• Advancedcontrolconceptsforcomponentsandoverallsystems,includingself-

learning control, uzzy logic and adaptive control

• Assessmentofnewheatdissipationoptions,usingtheairorgroundasaheat

sink. Heat dissipation devices must be adjusted to the various sizes and tempera-

ture levels o thermally driven cooling cycles and need to ocus on low:

water consumption;•

health risks;•

power consumption;•

initial costs;•

operation and maintenance costs.•

Advanced modelling and simulation tools or the thermodynamic analysis o•

systems and to support the planning and design o systems

Ways to integrate solar driven rerigeration systems with industrial processes•

Optimisation o large solar rerigeration plants•

Advanced control systems or the solar rerigeration systems (solar collection, cold•

production and cold storage charge and discharge)

Demonstration and technology transer

Commissioning procedures and guidelines•

Hydraulic concepts, design guidelines and proven operational and maintenance•

concepts or overall systems;

Identication o the most promising industrial applications or solar rerigeration•

systems;

Hybrid systems that combine compression technology with heat driven machines•

supplied with solar thermal heat and cold and (heat) storage

Installation and long-term monitoring o various systems in di erent congura-•

tions, sizes, climates and operating conditions

A set o standards or components and overall systems•

Documented experience in the practical operation o installations•Development o appropriate training materials or dierent levels o engineering•

education


90



Short term2008 – 2012


Long term 2020 – 2030

and beyond

Industry manu-

acturing and

technology transer

aspects

Production o•

small capacity

systems (e.g. or

residential ap-plication) on a

small industrial

scale

Initiation o•large-scale,

monitored

demonstration

programmes indierent regions

and sectors

Suitable com-•

missioning

procedures and

guidelines

Installation•

and long-term

monitoring olarge capac-

ity systems in awide variety o

congurations

and site condi-

tions.

Development•

o perormance

criteria

Cooperation•

with machinery

producer and

adaptation omachines or

solar cooling

Identication o•

the most prom-

ising industrial

applications or

solar rerigera-

tion systems inenergy and

economic terms

Large-scale•

industrial

production o

small capacity

systems

Proven systems•

concepts read-

ily availableor large-scale

implementation

Transer to•

proessionals on

a large scale.

Highly ecient•

and user-riendly

tools or systems

design

Adaptation o•

processes or

low and medium

temperature so-lar rerigeration

Solar cooling is•

part o standard

proessional

education at all

levels (installers,engineers and

planers)

8.3.4 Timetable

91





Long term 2020 – 2030

and beyond

Applied/advanced

technology aspects

New open liquid•

sorption cycles

with high stor-

age density

Cooled open•

sorption cycles

Development•

o integratedsolutions or thebest use o solar

rerigeration in

the industrial

process

Development•

o new hybrid

systems (solar

driven and

conventionaltechnology) or

dierent applica-

tions

Development•

o hydraulic

concepts, design

guidelines andproven op-

erational and

maintenance

concepts

Hybrid sorption-•

compression

cycle ready or

practical ap-plication

New cycles•

available or di-

erent technolo-gies (sorption,

ejector, open,

closed)

Design and•

optimisation o

large-scale solar

rerigerationplants

Compact closed•

machines or

application in

small capacity

range, includingautomotive

High density•

cold stor-age available

or industrial

application (e.g.

based on PCM

or thermo-chemical)

Advanced over-•

all solar cooling(and heating)

systems with

high integration


92





Long term 2020 – 2030

and beyond

Basic research

undamentals

Screening o•

new sorption

materials

Nano-coatings•

or heat

exchanger

developed

First design•models ondierent levels

(molecular,

micro-technol-

ogy)

Development o•

advanced cold

storage materi-

als

Development o•

new cycles (high

temperature

lit, higher COPand novel open

sorption)

Development•

o new heat

driven concepts

(e.g. thermo-

mechanicalprocesses such

as Rankine-

Rankine)

Successul•

laboratory

development o

advanced sorp-

tion materials

Availability o•

micro-fuid heat

exchangers orthermally driven

cooling

New heat•

exchanger ma-

trices, such as

metal oam

New storage•

materials

Powerul models•

or integrated

process model-

ling on dierent

levels (multi-scale models)

Development•

o new cycles

(double, triple

stage, novel and

open sorption)

Long-term,•

stable and cost

eective new

sorption materi-

als applicableon industrial

scale

93



By 2030, the solar building will have become a common sight. They will be attractive,

comortable and environmentally riendly. Its supply system will collect, store, distribute

and provide thermal and electrical energy. And it will be constructed mainly rom

multi-unctional building elements.

the building = the energy system

Multi-unctional components combine the unctionality o today’s standard compo-

nents (static, shelter rom weather and re resistance), with an ability to meet the

energy requirements o the building, by producing, storing, distributing or dissipating

heat.

Examples o multi-unctional building elements are:

Water pipes that also ull a structural unction•

Facade collectors that reduce heat loss rom buildings, serving as energy sources,•

heat sinks and/or stores, and provide shading

Roong elements that provide shelter, act as windows and as solar thermal•

collectors or PV modules, and which may be integrated with an energy storage

module

Walls that support the building or divide it into room, while acting as heat stores•

and thermal insulation

Disguised collectors: a special kind o acade or roo-integrated collector that•

imitates building materials and ts aesthetically with historic buildings

Intelligent building components, such as windows with sel adapting transmis-•

sion, based on the intensity o solar irradiance

Collectors that serve as a balcony foor, terrace, shading device, or semi-transpar-•

ent acade element

Some examples o multi-unctional components involving solar thermal or PV thathave already been introduced into the built environment include:

shading systems made rom PV and/or solar thermal collectors;•

acade-collectors;•

PV-roos;•

thermal energy roo systems; and•

Solar thermal roo-ridge collectors•

8.4 Multi-unctional components



94



Currently, undamental and applied R&D activities are also underway related to thedevelopment o:

transparent solar thermal window) collectors (see pic ture)•

acade elements consisting o vacuum insulation panels, PV-panels, heat pump•

and an heat-recovery system connected to localised ventilation (see picture)

Energy unctionality is insuciently integrated into the struc tural elements o build-

ings. Most multi-unctional components are also added on ater the construction o the

building. It would be cheaper to add them during construction. Solar thermal elements

could be integrated into preabricated attic expansions, oering a standardised and

thereore low cost way or people to build solar thermal into their lots.

Figure 28: Example: A solar thermal roo-ridge

collector is a “hidden” installation, which is

already used in a ew EU countries. It providessolar heat and also acts as a “standard” roo

ridge. It has been developed primarily as an

architectural solution to the integration o solaractive roo elements, which will not impede sub-

sequent roo alterations, such as the installationo a dormer window.

(Source: Inventum, The Netherlands)

Figure 29: Transparent solar thermal collector (let). (Source: Fraunhoer ISE, Germany)Figure 30: integral solar-active acade (right). (Source: www.smartacade.nl)

95



Manuacturing and installing multi-unctional building elements requires knowledge

that can rarely be provided by a single person or installation company. The elements

are unlikely to have the all advantages o all the building elements they replace without

any disadvantages. Building designers sometimes ail to choose the best combination

o multi-unctional elements or their budget.

Because so ew examples o their deployment exist, designers are reluctant incorporate

multi-unctional elements, earing they will break down and won’t resist bad weather.

The design o existing buildings is oten not ideal or the integration o new types o

energy systems. Perpetuating these design faws in new buildings must be avoided.

There is a lack o advanced simulation tools that dynamically describe the exergy

energy perormance, room temperature and air replacement rate o a building design.

Basic research

The optimal use o the limited building shell area requires structural demands in build-

ing components to be combined with solar unctions or heat storage and thin, highly

ecient insulation layers.

Phase change materials are a promising option or short and medium term heat stor-

ages. Knowledge is needed o how to integrate this type o storage into the building

when it is being constructed, or example in its walls.

Areas or development

Solar collectors that are part o the building shell need to be developed, as they

combine several unctions. They can be part o transparent acades and have daylight

and shading unctions, as well as their energy collecting unction. Collectors integrated

into opaque acades can protect against heat. In addition, they may act as a heat store

and/or supply system on the internal wall.

Measures to optimise energy gains o acade-integrated collectors are also needed,

such as partly tilted absorber components. Basic research in this eld needs to ocus

on materials and be closely linked to applied research on components.

Advanced coatings need to be developed or windows with switchable variabletransmission, or or collectors with controllable glazing transmission as well as ab-

sorptance. This is especially important or polymer-based collectors, in order to avoid

stagnation problems.

Advances are needed in tools or commissioning buildings as a whole, and methods

to ensure that predicted results are e ectively obtained by the building. Standards orthe hydraulic and electrical interconnectors o dierent building components are also

required.

8.4.3 Research agenda



96



Applied research

The limited available space or solar systems on the roo requires developments in

acade collectors and roo spanning systems to increase the usable surace area or

the harvesting o renewable (thermal) energy.

The development o a HUB interace, such as acade-integrated systems or solar

thermal collectors, would lead to ur ther standardisation and make a modular designeasible. In turn, this may lead to the development o modular replacement elements,

resulting in a complementary set o modular, multi-unctional components and

interaces - the HUB toolkit. Typical elements o this toolkit could be:

The distribution o heat and cold via pipes embedded in the construction, in•which liquids or gases circulate, carrying the heat or cold

Facade collectors used to collect a solar heat or radiate it in case o cold pro-•

duction, as well as or reducing heat loss

Roong elements that shelter and protect the building, or that let light into the•

building, while also generating or storing energy

Collectors designed to resemble the building elements o old buildings, espe-•

cially on the acade or roo

Windows with sel-adapting transmission, based on the intensity o solar radiation•

Demonstration

New components and supply systems need to be tested in new and existing build-

ings. Prototypes o the HUB interace and modular elements need to be built as

research into them goes on. This testing can be carried out at research laboratories

and test dwellings at R&D institutes. At this stage, limits o the HUB-toolkit should

also be determined.

When the HUB-toolkits are in the nal stage o development beore commercializa-

tion, complete HUB-toolkits should be made available through the construction and

supply industries. Once it has won the approval o these users, the toolkit can be

made available to housing corporations and the “do-it-yoursel” market.

Figure 31: Modular roo elements or solar thermal and solar electrical panels (with or without a window) in

combination with heat storage in the attic. (Source: ECN, The Netherlands)

97




Medium term2012 – 2020

Long term2020 – 2030

and beyond

Industry

manuacturing

aspects

Prototypes and•

possible struc-

tural compo-

nents, such asHUB-interaces

or existing en-

ergy systems

Design demands•or “missing

links” (sub- sys-

tems) estab-

lished

Denition o•

standardised

hydraulic andelectrical inter-

aces or the in-

terconnection o

dierent building

components

Proo o Manu-•

acturing HUB

interace and

sub-systems

Major part•

o identied

“missing links”

availableThe manu-•

acturing andconstruction

industry brings

several variants

to market, com-

bining uniqueand common

elements

Development o•

methods or the

integral planning

o buildingsDevelopment•

o commis-

sioning tools

and methods to

ensure that thepredicted results

are achieved by

the building

Large-scale•

implementation

realised

Do-it-yoursel•

renovation kits

available or

unplug-and-

replace energysystem compo-

nents

Dierent, optical•

identical roo

elements that

provide shelter

and ull dier-

ent unctionssuch as a win-

dow, solar water

or air collector,

PV module or

energy storagemodule

Invisible collec-•

tors

8.4.4 Timetable


98






and beyond

Applied/advanced

technology aspects

Set-up o com-•

mon language/

protocol or

energy systemsand modular

system compo-

nents

Set-up o com-•mon hydraulic

and mechani-

cal interaces

between collec-tors and acade

systems

Construction•

o prototypes

o rst HUB-

interaces

acade collectors•

used as (solar)

heat sourcesand heat sinks,

as well as orheat loss reduc-

tion

Collectors that•

also act as

fooring

Set-up HUB•

toolkit or reno-

vation

Intelligent build-•

ing compo-

nents, such as

windows with

sel-adaptingtransmission,

based on the

intensity o the

solar irradiance

Monitoring and•

optimisation o

HUB interaces

Development•

o modular

replacement

elements

99






and beyond

Basic research

undamentals

Establish reno-•

vation challeng-

es between end-

user demands(health, comort,

etc.), building

process require-

ments and

environmental

impacts (energy,material, etc.)

Inventory o•

alternative unc-

tions o struc-

tural building

components

Identication o•

“missing links”

Legal and/or•

architectural

restraints, orboundary condi-

tions

Building Process•

Innovation:

changing the

value chain

Development o•

“missing links”

Development o•

testing methodsand assessment

procedures orvarious com-

ponents o the

supply system

Development o•

advanced coat-

ings (e.g. or

window collector

glazing andabsorbers within

the collector),

with variableabsorptance and

transmittance

Systems study o•

new additions to

HUB toolkit

Solar thermal natural fow (thermosiphon) systems or domestic hot water production

do not require a pump as the circulation arises naturally through the dierence in den-sity between hot and cold water. However, natural fow systems only cover domestic

hot water demand. Forced circulation systems require a control system.

Typically, solar thermal control systems consist o a microprocessor controller, sensors

or the detection o input parameters, or example, temperature and radiation, and ac-

tuators, such as pumps and valves. Together, these components control the collection,

storage, distribution and emission o energy, thereby keeping the building’s climate in

line with the wishes o the building occupiers.

In some cases, solar thermal systems also require controllers to vent or send to a heat

sink low temperature waste heat.

8.5 Control systems


100



Solar thermal systems are requently part o more complex heating systems, or pos-

sibly cooling and/or ventilation (HVAC) systems. In turn, HVAC systems are themselves

part o a larger system (the building itsel, with its natural or specically designed

ability to store heat). Control systems that control only one sub-system are o ten sub-

optimal. Unortunately, today’s installations typically have separate controllers, which

do not talk to each other, or hot water production, space heating and cooling andventilation.

Today, most control systems are based on micro-processors. Sensors are typically

connected to the control system by wires. The control system can be based on simple

or complex algorithms depending on a ew or many parameters.

It would be best i one controller governed the whole HVAC system (and possibly

lightning and other electrical applications and related sub-systems installed in a build-

ing). What stops this happening is inadequate standardisation o the interaces and

communication between the dierent HVAC sub-systems. No standard exists or com-

munication between the sensors or the actuators and the control system, which leadsto unnecessary cost, since the same measurement (or example, the temperature in a

specic room) is oten taken by two separate sensors, each o which provides a signal

to a dierent controller.

The overall goal o uture HVAC control systems should be to operate the whole system

(e.g. a building) to minimise non-renewable energy consumption or a given set ting o

room temperature set by the users. Reaching the highest possible overall eciency im-

plies that one o the sub-systems may temporarily need to run at a sub-optimal level.

In order to overcome these problems, a detailed analysis o the energy fuxes within the

entire system (or example, the building) is required. It is necessary to consider all theenergy fows in a specic application and to develop one control centre or the entire

energy system. The controller should remember the preerences o individual users and

adjust the system according to these preerences while minimising energy consump-

tion. O course, the user should be able to override the system i it is not doing what (s)

he wants.

In addition, the controller should notiy the user when maintenance is required or when

a malunction is detected. Controllers should oer as standard the ability to compare

the perormance o the system they control with reerence values or an optimised

system operating under the same conditions (external temperature, solar radiation,internal temperature and hot water load).



101



Basic research

Worldwide survey and benchmarking o available technical solutions•

Survey o available control equipment and control strategies•

Scenarios or user expectations o control systems in 2030•

Improvement o system and building simulation and design tools, in order to take•

into account all comort parameters, such as temperature, humidity and light, as

well as energy consumption.

Methods to assess the environmental perormance o the building as a whole over•

its lietime are required. A common platorm or the simulation data exchangebetween dierent s takeholders should be dened

Development o advanced control equipment or the supply system that is easy to•

use and standardised

sel-adapting and sel-optimising strategies

control systems responsive to weather orecasts

user riendliness

integration o new automated methods, such as “uzzy logic” controllers and

control algorithms based on optimisation theory

the development o cheap and intelligent (or example, sel-adapting)

sensors, or the usage o “virtual sensors”, estimating process conditionsusing mathematical models instead o, or in conjunction with physical

sensors. Virtual sensors can be used i a physical sensor is too slow, too

expensive or too complicated to be maintained

early detection o aults in the system

monitoring perormance with advanced communication technologies like

wireless

the integration o data acquisition and evaluation

Development o communication platorms or data exchange between dier-•

ent components and the controller. These platorms can be based on wireless

technologies or networks that already exist and are used or other purposes. This

communication platorm can also act as an inter ace or a “hardware-in-the-loop”simulation and testing o control strategies on the real system.

Development o methods or the planning o the entire system/building, taking into•

account preerences or comort, energy consumption, resources used and costs

during the building’s lietime (lie-cycle costs)

Development o commissioning tools and methods in order to ensure that the•

orecast results are really obtained by the system

Development o a standardised method or the assessment o the overall perorm-•

ance o the system/building and or checking i the requirements o the energylabel are ullled


102



Applied research

Development o the supply system:

Development o one centralised control system or the entire energy system. This•

means a system or the collection, storage, distribution and release o thermal

energy

The centralised control system should use all available sources or the collec-•

tion o energy, such as solar radiation, ambient air, waste water and air, and the

ground beneath and/or around the building.

The centralised control system should manage the heat and cold stores in the•

system.

With regard to the release o excess energy (or example, rom a cooling ma-•

chine), the centralised control system should sent it to the most appropriate heat

sink (ambient air, perhaps, via solar collectors, waste water, the ground).

Demonstration

On-site testing o centralised controllers in new and old buildings, as well as k inds o

energy systems such as solar process heat plants.

Capacity building

Training or technicians who will install the advanced centralised controllers. Peoplemust be trained in monitoring the system, to a deeper level than the installers.

103



Short term 2008 – 2012


Long term 2020 – 2030

and beyond

Industry

manuacturing

aspects

Survey and•

benchmarking o

currently avail-

able technicalsolutions and

experiences

Denition o•

standardisedelectrical

interaces or

the interconnec-

tion o dierentsensors and

actuators to the

control system

Development o•

methods or the

integral planning

o the building / system as a

basis or the pro-

gramming o the

control system

Development o•

commissioning

tools and meth-

ods to ensurethat predicted

results are re-

ally obtained by

the building /

system

Wireless con-•

nection o mo-

bile units to the

control systemas user interace

(e.g. or display-

ing the system

status and user-

based interac-

tion)

Applied/advanced

technology aspects

Further develop-•

ment o sel-

learning / sel-adapting controlstrategies

Development o•

advanced con-

trol equipmentor the entireenergy system

Advanced build-•

ing compo-

nents, such aswindows withcontrollable

transmission

Basic researchundamentals

Determination•

o user expecta-

tions or the con-

troller / building

in 2030

Development o•

testing methods

and assessment

procedures or

dierent com-

ponents o the

supply system,especially with

regard to con-

troller dependentbehaviour

Strategies or•

the wireless

determination o

the user opera-

tion parameters

(such as

temperature)and senses (or

example eeling

hot or cold)

8.5.3 Timetable


104



This chapter reers to thermally driven, decentralised water treatment systems, such

as sea water desalination), which provide high quality drinking water to isolated cus-

tomers, such as single households, small- to medium-sized communities and remote

resorts. The needs o di erent target groups map to three categories o system sizes,

each based around a dierent combination o technologies.

Small-scale solar driven desalination processes

(0.01 to 0.5 m3 /day)

This size is typically required or individual buildings. Typical technologies within this

scope are:

Classical solar stills without heat recovery•

Watercone® technology•

Multiple eect solar stills applying limited and very easy heat recovery•

Small-scale membrane distillation units•

UV disinection using PV, photocatalytic disinection•

Medium-scale solar driven low temperature thermal desalination processes

(0.5 up to 100 m³/day)

These processes are typically used or hotels, holiday resorts and small communities:

Multi-eect Humidication Dehumidication process, MiniSal™ MidiSal™,•

MegaSal™ units

Membrane distillation units•

Other new processes (solar MED, solar MSF)•

Mid-scale hybrid electricity and water generation (up to 1 MWel and 500 m³/day water)

Combined Heat and Power (CHP) generators, solar assisted thermal share•

Use o waste heat rom diesel or vegetable oil-based generators•

Multi Eect Solar Desalination•

8.6 Water treatment (desalination)

105



Large-scale combined thermal electricity and water generation

(rom 500 m³/day and 0.2 MWel)

These installations can cover the needs o larger communities, and medium- to large-

sized tourist resorts. The typical technologies used in them are solar thermal power

plants using parabolic trough or Fresnel collectors, with steam generators or electricityproduction and waste heat used or desalination.

Renewable energy-driven water disinection or grey water recycling

Solar driven catalytic water disinection•

PV driven ultraviolet radiation disinection•

Industrial water treatment by renewable energies

Recent research activities on solar powered membrane distillation (MD) systems ocus

on small and medium-scale seawater desalination units. MD, as an innovative and

alternative desalination process, diers rom conventional membrane technologies like

reverse osmosis (RO), in that the membrane is permeable only to gas or vapour and

impermeable to liquids. Thermal energy, such as solar heat or waste heat, can be usedor phase changing, and thereore or the separation process. In the reverse osmosis

process, pressure is used to orce a liquid through the membrane, which retains salts

and other dissolved matter. This makes the system energy intensive and, especially or

small seawater desalination units, uneconomical.

The implementation o small and medium-scale solar powered membrane distilla-tion units in industry is still unusual, although MD is a well-known technology and, in

principle, suitable or puriying water, dewatering waste liquids and generating con-

centrates (ood industry). The main barriers to this technology are the low permeate

fow rate, MD membranes and the integration o solar heat systems into industrial MD

applications. Future research work in the eld o MD should ocus on these areas.

Solar stills are already widely used in some parts o the world (or example, Puerto

Rico) to supply water to households o up to 10 people. The modular devices supply

up to 8 litres o drinking water rom an area o roughly 2 m². The potential or technical

improvements is to be ound in reducing the cost o materials and designs. Increasedreliability and better perorming absorber suraces would slightly increase production

per m².

Multiple Eect Humidifcation (MEH) desalination units indirectly use heat rom highly

ecient solar thermal collectors to induce evaporation and condensation inside a

thermally isolated, steam-tight container. By solar thermally enhanced humidication



106



o air inside the box, water and salt are separated, because salt and dissolved solids

rom the fuid are not carried away by steam. When the steam is recondensed in the

condenser, most o the energy used or evaporation is regained. This reduces the en-

ergy input or desalination, which requires temperatures o between 70 and 85°C. Over

the years, there has been considerable research carried out into MEH systems and they

are now beginning to appear on the market.

The thermal eciency related to the solar collector area is much higher than or solar

stills. The specic water production rate is in the region o 20 to 30 litres per m² ab-

sorber area and day. At the same time, the specic investment is less than or the solar

still, as the solution is available or sizes rom 500 up to 50.000 litres per day.

Membrane distillation (MD)

Membrane distillation is a separation technique, which links a thermally-driven distilla-

tion process with a membrane separation process. The thermal energy is used or turn-ing water into vapour. The membrane is only permeable to the vapour, and separating

the pure distillate rom the retained solution. MD oers important advantages or the

construction o solar driven, stand-alone desalination systems or applications where

waste heat is available.

Fraunhoer ISE is developing solar driven compact desalination systems, using MD orcapacities between 100 and 500 l /day, and larger systems ranging up to 20 m³/day.

All systems are solar energy-driven, but could also be operated with waste heat. The

electricity or auxiliary equipment, such as pumps and valves, could be supplied by

photovoltaic modules.

Five compact systems or resh water capacities o about 100 l/day and two dou-

bleloop systems (1x 1000 and 1x 1600 l/day) have been installed in dierent test

sites.

Higher investment costs: unortunately, all renewable energy driven systems have

high upront costs and take a long time to pay or themselves. This is caused mainly by

the cost o supplying heat (or example, solar thermal collectors and thermal storage),rather than by the cost o the desalination modules. Desalination systems must be

designed to last a long time and require little maintenance.

This adds to the costs, making this technology prohibitively expensive or end users,

unless subsidised.

Lack o suitable design guidelines and tools: worldwide, there are only ew specialists

in solar desalination installations. More people must be trained in the technology.

Awareness: Too ew people are aware o the potential o renewable-energy-drivendesalination technology. National or regional development plans or water systems

oten only consider centralised solutions. The economic and practical advantages o

decentralised solutions, based on solar energy, need to be highlighted.

8.6.2 Barriers to increased deployment

107



Basic research

R&D on new/innovative materials (low cost/high durability) or ecient thermally-•

driven heat and mass t ranser (evaporation and condensation

Polymer science (unctional material oils and abrics, heat conducting polymers)•

- Market research

Multi-water quality generation, combination o desalination methods, such as,•

RO/MEH

Multi-stage thermal desalination, salt production with high recovery rate o 30 to•

50%

Chemical-ree raw water pre-treatment•

Applied research

Increase the eciency o solar power generation or desalination purposes•

House- / building-integrated desalination system designs; desalination becomes•

part o house technology

Systems that are easy to build and maintain or decentralised, small-scale•

applications, which do not need an external power supply (electricity or uel)

New solar collectors and storages adapted or the needs o solar desalination•

systems: mid temperature (90 -50°C, resistant against salty sea air)

Combination o solar thermal desalination and power generation•

Multi-stage desalination, applying several processes consecutively, in order to•increase recovery up to 75%

Integration o desalination devices in buildings•

Systems designed or ease o use•

Awareness raising o solar thermal driven desalination as a cost ecient and•

reliable alternative

Finding o the limits o the production range o possible systems•

Demonstrate consistent system perormance ater long periods o operation•

Development o low cost and robust designs to make it easier to deploy in•

environments where specialists will rarely, i ever, be able to repair or maintain it

Demonstration

Building integration•

Ease o operation, conrmation o low energy demand•

Awareness raising o solar thermal driven desalination as a cost ecient and reli-•

able alternative

Clarication o the wide production range o possible systems•

Continuous operation and permanent water quality•

Development o low cost and robust concept or easy technology transer•

8.6.3 R&D needed to achieve the goals


108






and beyond

Industry

manuacturing

aspects

Quality control•

Maintenance•

control and

implementation

Cost reduction o•

system

Standardisation• o testing criteria

or water and

energy demand

Easy and main-•

tenance ree

water pre-treat-

ment or thermaldesalination

without ouling

and scaling

Envisaged: e-•

ciency increase

o thermal proc-esses depending

on the capacity

System design•

or small ap-

plications

Cost ecient,•

integrated

transport casingdesigns

Mass production•

Further cost•

reduction at

stable quality

and durability

Lean production,•

easy design

or assemblyin countries o

application

Standardisation•

and implemen-

tation o systems

Permanent qual-•

ity control by

remote control

Maintenance•

control andimplementation

Further cost•

reductions

8.6.4 Timetable

109






and beyond

Applied/advanced

technology aspects

Minimisation•

o additional

electrical energy

demand

Optimisation o•

operation and

maintenance

Easy and main-•tenance reewater pre-treat-

ment or thermal

desalination

without ouling

and scaling

Envisaged: e-•

ciency increase

o thermal proc-

esses dependingon the capacity

System design•

or small ap-plications

Cost ecient,•

integrated

transport casing

designs

Building inte-•

grated system

designs - desali-

nation becomes

part o housetechnology

Easy to build•

and maintainsystems or

decentralised,

small-scale ap-

plications with-

out the need orexternal power

supply (electric-

ity, uel)

New solar col-•

lectors and stor-

ages adapted

to the needs o

solar desalina-tion systems:

mid-temperature

(90 -150°C,

suitable or long-

term resistance

to an aggressivesea-side atmos-

phere

Combination o•

solar thermal

desalination and

power genera-

tion

Multi-stage•

desalination

applying sev-

eral processesconsecutively, in

order to increase

recovery up to

65%

Standardisation•

Quality control•

Maintenance•

control and

implementation

Cost reduction•


110






and beyond

Basic research

undamentals

R&D on new/ •

innovative mate-

rials (low cost/

high require-ment) or e-

cient thermally

driven heat and

mass transer

(evaporationand condensa-

tion)

Eciency•

increase o solar

power genera-

tion or desalina-

tion purposes

Polymer science•

(unctional

material oils

and abrics, heatconducting poly-

mers) - market

research

Multi-water•

quality genera-

tion, combina-

tion o desalina-

tion methods

Multi-stage de-•

salination, salt

production, highrecovery 30 to

50%

Develop low•cost and robust

concept or

easy technology

transer

Standardisation•

Quality control•

Maintenance•

control andimplementation

Cost reduction•

New materials•

and processes

111



112

Fraunhofer Lines Diagram. SPECTRUM OF VISIBLE LIGHT from the Sun

shows a continuum of colors crossed by dark absorption lines

Source: http: //de.wikipedia.org/wiki/Bild:FraunhoerLinesDiagram.jpg

(created by NASA)





113




Research Inrastructure9



This chapter indicates a number o requirements or the development o research inra-

structures, which are necessary to implement ESTTP’s Strategic Research Agenda.

Following the defnition proposed by the European Roadmap or Research Inrastruc-

tures, published in 2006 by the European Strategic Forum on Research Inrastructures,

Research Inrastructures are “... acilities, resources or services o a unique nature thathave been identifed by pan-European research communities to conduct top-level

activities ... Research Inrastructures may be single-sited, distributed, or virtual ...”

Under this defnition, Research Inrastructures include human resources, equipment, as

well as repositories o knowledge, such as archives and databases. In general, such

inrastructures are costly and are most e fciently set up at a pan-European level.

As a specialised pan-European research and industry platorm, the ESTTP has identi-

fed a need or Research Inrastructures at European level in the ollowing areas:

Solar assisted cooling and air-conditioning•

Medium-temperature (process heat) collectors•

Heat storage•

Compared with other energy technologies that require billions o Euros in R&D

investment, solar thermal R&D is cheap. Furthermore, solar thermal is highly likely to

produce applicable results within a relatively short time.

Basic and applied research in the feld o thermally driven cooling is currentlydominated by Japan and, increasingly, China (the USA led the market in the 1980s).

Europe lagged behind or some time, but due to advances in the efciency o energy

transormation chains, European R&D institutes and universities have been increasing

their eort s on thermally-driven cooling technology, and specifcally on its operation

in combination with solar energy. Today, Europe is one o the global leaders in theimplementation o solar thermal cooling technology.

In several EU countries, research inrastructure or basic and applied research in this

feld is airly well established. There is defnitely a need or a well-organised exchangeon test standards or new machines and cycles. A joint eort or large-scale demon-

stration is needed to ensure successul market introduction. At the same time, the nextphase o development will require ocus on technology transer, widespread demon-

stration projects and training.

9 Research Inrastructure

9.1 Solar assisted cooling and air-conditioning


114



A structured collaboration among European research institutes and industry will sup-

port rapid commercialisation o solar driven cooling technologies, strengthening the

European dimension o this industrial sector. This collaboration should consist o:

RD&D Network •

One “Joint European Laboratory”•

Regional Solar Cooling Development Centres or demonstration, technology•

transer and training

Networking activities can lead to a powerul e ective exchange between those in-volved in the sector’s R&D, which will reinorce European leadership and guarantee the

rapid achievement o optimal technology development. The required inrastructures orthese networking activities are mainly virtual.

Concerning physical inrastructures a Joint European Solar Heating and Cooling

Laboratory, must be built. In this Laboratory, the common eorts o institutes activein solar energy research, process engineers, and rerigeration experts will lead to the

development o European products or the Mediterranean, Asian and other markets.

This centre should be situated in Southern Europe to take advantage o the higher cool-

ing demand and solar resource. The laboratory will be a decentralised acility or theEuropean researchers and industry (who are mainly based in northern countries), o-

ering the opportunity to test components or systems under real lie conditions (e.g. (1)

medium temperature collectors, based on concentrating technologies, that need a high

ratio o direct to global radiation. (2) thermally driven systems, which can be tested

under hot and humid climate conditions). Such a research inrastructure should also

be used or collaborative research work connected to the use o solar thermal technolo-gies that are not directly connected to cold production, or example, desalination.

While the inrastructures or R&D and testing should ideally be set up at a European

level in the Joint Laboratory discussed above, a small number o Solar Cooling Devel-

opment Centres should be set up at national or regional level in high potential regions

(all the Mediterranean basin and Southern Balkans). In the next phase o development,hundreds o systems will be installed in each o these regions. Visible and well man-

aged demonstration projects or dierent applications will be important, and the moni-

toring o their perormance and good access to this monitoring data will accelerate

innovation. Well trained engineers and installers will do installations o high quality,

achieving big energy savings or their customers and a helping to make the market or

solar thermal sel-sustaining. These activities should ideally be supported by regionalcentres, working in the local language and in close contact with the local market.

115



The research inrastructure available or the research and development o process heat

collectors is barely adequate.

Some research institutes are broadening the scope o their work in high temperature

collectors or solar thermal power generation to include process heat collectors (or

example, CIEMAT in Spain, and DLR in Germany), while others are coming at processheat collectors rom a background in low temperature collectors (or example, Fraun-

hoer ISE in Germany, AEE INTEC in Austria, SIJ in Germany, SPF in Switzerland and

INETI in Portugal).

No testing acilities specifcally designed or process heat collectors exist in Europe to-day. The Joint European Solar Heating and Cooling Laboratory (outlined above), could

be the place to test new components or medium temperature applications in outdoor

conditions and serve as a centre or networking and inormation-sharing among mem-

bers o the research community.

As discussed above, the development o advanced thermal s torage technologiespresents substantial R&D challenges. The broad scope o this work should ideally be

addressed on a European scale with dierent industrial sectors (solar thermal, cogen-

eration and district heating) involved where relevant.

The launch o a virtual or real “European Institute for Thermal Energy Storage” would

be helpul. It could help:

scientists to work at each other’s acilities, or visit them•

Scientists to share research inrastructures (testing equipment and communication•

tools)

Strengthen MSc and PhD courses in solar thermal by accessing Europe’s leading•

experts in this feld

Through the outstanding reputation o the European Institute or Thermal Energy S tor-

age it will be much easier to att ract specialists rom other important research felds,

especially materials scientists. The contribution o other felds is o key importance toopen up new ways or arriving at more compact thermal energy storage systems.

An institute also better supports the long term challenge that compact thermal energy

storage poses. Only with a long term programme it is possible to couple basic science

with applied science and engineering. The institute is one o the pillars or such a

progamme.

The research inrastructure necessary or the institute ranges rom specialised analyti-cal equipment or materials research and development, through computing acilities or

specialised numerical modeling technology developments, to dedicated equipment or

component and system testing at medium and high temperatures.

9.2 Process heat collectors

9.3 Heat storage


116



117



118





119




10 Reerences



Ecoheatcool 2006: The European Heat Market, Eurohat & Power, 2006.

www.euroheat.org

EREC 2006. European Renewable Energy Council.

www.erec-renewables.org/deault.htm

ESTIF 2003: Sun in Action II, A Solar Thermal Strategy or Europe.

European Solar Thermal Industry Federation.

www.esti.org/fleadmin/downloads/sia/SiA2_Vol1_fnal.pd

ESTIF 2007: Solar Thermal Action Plan or Europe, January 2007.www.esti.org/stap

ESTIF 2007a: Preliminary analysis o ST market in 2007.

not yet published at the time o writing this document.

ESTTP 2006: Solar Thermal Vision 2030, vision o the usage and status osolar thermal energy technology in Europe and the corresponding research

topics to make the vision a reality.

www.esttp.org

EUR Delphi 2004: European Energy Delphi. 2004. Technology and social

visions or Europe’s energy uture: a Europe wide Delphi s tudy. Final Report.EurEnDel project.

Institute or Futures Studies and Technology Assessment (IZT).

Eur. Com 2003: European Commission, DG TREN, 2003. Clean, save andefcient energy or Europe: impact assessment or non-nuclear energy projects

under the Four th Framework Programme.Rep. EUR 20876/2, EC, Brussels.

10 Reerences

10 Reerences

120



GCDMS, 2007: Global Climate Decision Makers Survey.

GlobeScan, The World Bank, ICLEI, IUCN, World Energy Council, World Business

Council or Sustainable Development, and others:

www.iucn.org/en/news/archive/2007/12/10_climate_change_survey.pd

IEA 2006. Barriers to technology diusion: the case o solar thermal technologies.International Energy Agency.

OECD/IEA, Paris, 2006.

IEA 2007. Weiss, W., Bergmann, I., Faninger, G.: Solar Heat Worldwide, Markets

and Contribution to the Energy Supply.IEA, 2007.

IEA 2007a: Renewables or Heating and Cooling – Untapped Potential.

IEA, Paris 2007.

POSHIP 2001: H. Schweiger et al., The Potential o Solar Heat or IndustrialProcesses, Final Report, 2001.

http://www.solarpaces.org/Library/csp_docs.htm

Sarasin 2007: Sustainability Report 2007.

Solar Energy 2007 – The industry continues to boom, Switzerland 2007.

Solar Thermal Vision 2030.

European Solar Thermal Technology Platorm, Brussels, May 2006.

Sun & Wind Energy 2007. Sun & Wind Energy.international issue 4/2007, Bieleeld 2007.

Solar Thermal (3)

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