The future of Greenhouse Industry – from energy consumer to energy supplierCanadian Greenhouse Conference, 5 October 2016, Niagara Falls, Canada

Dr. Silke Hemming, Wageningen University & Research Centre

Energy saving goals in The Netherlands

Energy agreement 2014-2020

Goals:

● Maximum total CO2 emission of 6.2 Mt y-1 in 2020

● Maximum total energy consumption (111.9 PJ in 2013) reduced by 11 PJ in 2020

Ambition:

● New build greenhouses climate neutral in 2020

● Existing greenhouse use Next Generation Cultivation Strategies

● Greenhouse sector completely sustainable in 2050

Energy saving in 2013

CO2 emission total 6.8 Mt (goal 2020=6.2 Mt)CO2 emission in cultivation 4.9 Mt (goal 2020=5.8 Mt)

Use of sustainable energy sources 2.9%(goal 2020=20%)

Energy efficiency -56% primary fossil fuel per unit product (goal 2020=57%)

Energy saving in 2013 implementation at commercial growers

Sustainable energy: geothermal 134 ha, solar energy (semi-closed greenhouses) 237 ha, bio-diesel 132 ha

Next Generation Cultivation Strategies (mechanical dehumidification) 146 ha

Diffuse glas 123 ha

Co-generation 6955 ha = 2.35 Mt CO2 reduction,

IDC Energy

What: innovations for energy saving in greenhouse production by new technologies and new cropping strategies

Who: Wageningen UR, greenhouse supply industry, grower

IDC Energy - research issues 2015/2016

IDC Energy - research issues 2015/2016

Principle of Dyalight greenhouse

Principle of Fresnel lens greenhouse Linear Fresnel lenses in roof to concentrate direct solar radiation CPV or thermal to collect concentrated sunlight (direct PAR & NIR) Production of electricity or heat Control of sunlight on plant level Diffuse PAR light used for potplant production

500 m2 prototype greenhouse in Bleiswijk, The

Netherlands

Daylight greenhouse – Fresnel lens and thermal collectors

Daylight greenhouse: upscaling to practice

Ter Laak orchids - thermal collector, insulated with double glas, dehumidifcation● Heat demand reference: 1275 MJ/m²

● Heat demand DLG: 1020 MJ/m² (20% saving)

● Heat collection DLG: 435 MJ/m² (35% saving)

IDC Energy - research issues 2015/2016

Diffuse light

Photosynthesis● Horizontal light distribution more equally

● Vertical light penetration in crop; diffuse light more absorbed by middle leaf layers

● Higher photosynthetic capacity in those leaf layers

Morphology and Development

● Higher LAI

● More generative growth and faster fruit development, heavier fruits

Up to 10% higher yield by diffuse light(e.g. Hemming et al., 2006; 2008; Dueck et al;, 2012; Li, 2014)

“Winterlight greenhouse”

Goals: >10% more natural sunlight in greenhouse during winter months (October-March) and >10% higher light use efficiency crop Innovation elements:

● Greenhouse roof construction – roof shape, angle, orientation, materials

● Glass – basic glass, diffuse structure, AR coating, condensation behaviour

● Screen – basicmaterial, installation

● Crop – high-wire cucumber, cultivars, cropping system, crop management

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Raytracing modelling –roof angle

Venlo-type roof Orientation gutter East-West Diffuse glass Optimum angle 20-30°

Transmission greenhouse roof based on daily light integral PAR [%]

Swinkels et al. 2015

Raytracing modelling –roof orientation

Venlo-type roof Roof angle 23o

Diffuse glass Optimum orientation East-West

Transmission greenhouse roof based on daily light integral PAR [%]

Swinkels et al. 2015

Raytracing modelling –Multi-tunnel, round-arched roof

Round-arched roof Different shapes, convex, concave,

different diameters Orientation gutter East-West Always light losses 3-7% (without construction)Transmission greenhouse roof based on daily light integral PAR [%]

Swinkels et al. 2015

Glass: optimum AR coating

Angle of light incidence on greenhouse roof (one configuration) during Oct.-Mar.

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40

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60

70

80

90

100

0 20 40 60 80

Ang

ular

tra

nsm

ittan

ce [

%]

Angle of incidence [o]

DA15E_dry DA15F_dry DA15K_dryAngle of incidence [o]

Percentage of sunlight based on light integral and surface [%]

Opt

imum

ang

le

Opt

imum

ang

le

DA15K DA15K+AR DA15K+opt.AR

Angular transmission of light by covering material (diffuse glass) different AR coatings

Glass: condensation behaviour

Condensation inner side roof depending on greenhouse configuration, outside climate, humidity setpoints, crop type

Calculations with KASPRO (de Zwart, 1996), crop tomato

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60

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0 20 40 60 80Ang

ular

Tra

nsm

issi

on [

%]

Angle of incidence [o]

DA15K_dry DA15K_wet2

Percentage daytime hours inner side roof wet [%]

Angular transmission of light by covering material (diffuse glass) dry and wet

DA15K dry DA15K wet

IDC Energy - research issues 2015/2016

Goal: Greenhouse concept with highest energy saving and good tomato production● Double glass

with low u-value and high light transmission

● Mechanical dehumidification with heat-regain

● “Next Generation CultivationStrategies” (climate control)

VenLowEnergykas

● Double glass● low u-value due to

low-ε coating● high light transmission due to

AR coating

VenLowEnergykas – double glass

Glass Coating Th U-value

Single - 82 6.7

Single AR-AR 91

Single AR-Low-ε 81

DoubleAR-AR-Low-ε-AR 79 1.2

Hemming et al. 2012

Argon

VenLowEnergykas: energy consumption

Kempkes et al. 2014

50% saving

70% saving

VenLowEnergykas: crop production tomato (cv. Komeett)

Kempkes et al. 2014

01020304050607080

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Pro

du

ctio

n t

oam

to c

v.

''Kom

eett

'[kg

m-2

]

week number2011 2012 2013 2014

Prediction: 70 kg m-2 y-1

Comparable to commercial growers

Humidity control – higher setpoint

Crop transpiration [kg m-2 y-1]

Evaporation in periods without heating

48 kg m-2 y-1 saving possible

Setpoint for relative humidity [%]

Evaporation in periods with heating

De Zwart et al. 2014

Humidity control – higher setpoint –lower crop transpiration during night

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50

100

150

200

17-Jan 16-Feb 18-Mar 17-Apr 17-May 16-Jun 16-Jul 15-Aug 14-Sep 14-Oct 13-Nov

20132014

Crop transpiration night [l m-2]

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17-Jan 16-Feb 18-Mar 17-Apr 17-May 16-Jun 16-Jul 15-Aug 14-Sep 14-Oct 13-Nov

20132014

VenLowEnergykas 2013/14

De Gelder et al. 2015

VenLowEnergykas: upscaling to practice

ID Kas® Duijvestijn tomato grower High insulation with double glass

with AR coating and diffuse structure (no low-ε coating)

“Next Generation CultivationStrategies”

2SaveEnergykas®

Goal: Greenhouse concept with high energy saving and high production at limited level of investment New Venlo-greenhouse with

insulated covering, flexible

Glass with AR coating and diffuse F-CLEAN® inside for insulation and high light level

Small ventilation windows

“Next Generation CultivationStrategies” and dehumidification

2SaveEnergykas®: glass & F-CLEAN®

Glass F-CLEAN®

always 1 layerdiffuse

Glass

F-CLEAN®

Kempkes et al. 2015

Hemispherical transmission τh and the haze η of different combination of materials for PAR light 400- 700 nm

2SaveEnergykas®: light transmission

Material Hazeη

Hemisphericallight transmission

τh

glass clear + Fclean diffuse 77 72.6

glass clear + AR coating + Fclean diffuse 77 75.9

glass diffuse high haze + Fclean clear 68 75.3glass high haze + AR coating + Flcean clear 68 80.7

Kempkes et al. 2015

Predicted: 19 m3 gas m-2 y-1

(ca. 40% saving compared to practice)

Realisation: 15.5 m3 gas m-2 y-1

Commercial practice: 31 m3 gas m-2 y-1

2SaveEnergykas®: energy consumption

Kempkes et al. 2015

50% saving

2SaveEnergy kas®: crop productiontomato cv. ‘Cappricia’

Predicted: 63 kg m-2

Realisation: 67.1 kg m-2

Kempkes et al. 2015

Summary

Thank you for your attention!

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