Assessment of Technologies for Mitigating Global Warming · Rectenna DC power Micro wave Power...
Transcript of Assessment of Technologies for Mitigating Global Warming · Rectenna DC power Micro wave Power...
Assessment of Technologiesfor Mitigating Global Warming
Yoichi KayaResearch Institute of Innovative
Technology for the Earth ( RITE ) , Japan
Contents
1. Threats of global warming 2. Mitigation scenarios 3. Nuclear power: its role and future issues4. Wind power and photovoltaics: their trends
and limitations5. Biomass6. Other renewables7. Role of CCS8. Concluding remarks
Mechanism of Breakdown of Thermohaline circulation
Rise in temp. of North Atlantic
Melting of ice and snow
More rainfall
Lighter surface water
Less driving force of water sinking down
Breakdown of thermohaline circulation
-20 -10 0 10 20 30
>5,000
3-5,000
1-3,000
<1,000
2004
1957
Depth: m
Speed Svnorth
Fig. Slow down of thermohaline circulation in the Atlantic
Source:Bryden,H.L. et al, Nature, Dec.2005
0
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400 500 600 700 800 900 1000 1100 1200
CO2 concentrations (ppmv)
Prob
abili
ty o
f TH
C c
olla
pse
(%)
Murphy(2004)Annan(2006)Hegerl(2006)
Fig. Possibility of the Collapse of Thermohaline Circulation (THC)
CO2 concentration in the air-present and future-
1. 1800 280 ppm2. Present 380 ppm3. EU 2 degree target 450 ppm
( due to M.Weiss, March, 2005)4. Avoidance of THC collapse 550 ppm
( with 90 % confidence )
ppmCO2 concentration in the air
Fig. CO2 emission for stabilizing its concentration in the airSource: IPCC TAR technical summary
550ppm
Presentlevel
Reforestation
CO2
Sequestration
Nuclear Power
OtherRenew. Energy
Photovoltaics
Fuel Switching
Energy Saving
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5
10
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25
2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100Year
Car
bon
emis
sion
s an
d re
duct
ions
(GtC
/yr)
Energy SavingFuel SwitchingPhotovoltaicsOther Renewable EnergyNuclear PowerCO2 SequestrationReforestationNet CO2 Emission
among Fossil Fuels
Net Carbon Emissionsin 550ppmv Case
Net Carbon Emissionsin Reference Case
Technological Options for 550 Technological Options for 550 ppmvppmv StabilizationStabilization
Non-carbon primary energy
1. Nuclear power2. Renewables (‘new’ )1) wind power / photovoltaics2) biomass 3) geoheat and other ambient energy4) space solar power (SSPS)
3. Fossil fuels with CCS
0 20 40 60 80 100
U S A
U K
G erm any
Finland
Japan
S w itzerland
K orea
S w eden
B elgium
France
nuclear
%
Fig. Share of nuclear in power supply (kwh、2001)
World average
Rate of change in carbon intensity of primary energy : 1980-2000
Carbon intensity = CO2 emission
primary energy
actual data nuclear moratoriumat 1980
OECD coutries
Japan
- 0.6 % / year
- 0.5 % / year
0.0 % / year
+ 0.3 % / year
Future key issues on nuclear power
Basis: Nuclear is almost indispensable in decarbonized future.
1. How to scrap and build present reactors?ex. Japanese case ( see the figure )
2. How and where to dispose nuclear wastes?3. How to improve public acceptance?
0
500
1000
1500
2000
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3000
3500
4000
4500
5000
1 4 7 10 13 16 19 22 25 28 31 34
原発容量
万kw
年図4.日本の原発の累積年齢構造(容量ベース、2004年現在)
201020202030 40歳到達時期
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Germ
any
Spain
USA
Denm
ark
India
Italy
Neth
erland
s
Japa
nwind power
GW
Fig. Capacity of wind power(2004)
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'95 '96 '97 '98 '99 '00 '01 '02 '03 '04
w ind pow er
GW
Fig. Total capacity of wind power ( World)
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1200
Japa
nGe
rman
y
USA
Aust
ralia
Neth
erland
s
Spain
Italy
Fran
ce
PV
MW
Fig. Capacity of Photovoltaics (2004)
3.4 % (2030)0.9 GWJapan
20% ( 2030)3.1 GWDenmark
6 % (2020)6.8 GWUSA
---------8.3 GWSpain
25% (2025)16.6 GWGermany
Future target( % of elec.power )
Capacity(2004)
Table. Present and future target of wind power
Output changeability of wind power / photovoltaics
1. Outputs of wind power and photovoltaics(WP/PV) change randomly with time.
2. Some of grid power plants are used for satisfying the relation
total supply = total demand3. Then
the facility cost of these grid power plants
external cost of WP/PV due to output changeability
External cost of WP / PV- Japanese case -
1. Corresponding power plants :oil fired power plants
2. Their capacity utilization ratio: low20 -30 %
3. Costs 10 -14 Yen per kwh ( 8 – 11 US cents )
Limits of WP / PVdue to output changeability
1. Their output changeability innevitably requires installation of those power plants which adjust their outputs so as to satisfy the condition
total supply = total demand2. Facility costs of these power plants are
additional costs of the grid solely due to introduction of WP/PV. = too heavy burden→ capacity of WP/PV << grid capacity
traditionalhydropowerheatbiofuel
New renewables biofuel
Fig. Renewables in the world:2002
Traditional use
Key issues of new biomass- when large production needed -
1. Low energy conversion efficiencysolar E to biomass: 1-2 % how to improve it?
2. Competition with food productionenergy plants such as potatoes, sugarcanesand corn are eatable
Possible solution: utilization of plant wastessuch as plant leaves, stems, etc.
Two candidates for future renewable energy supply
1. Use of ambient energy resources forlow temperature heat supply ( residential )
2. Space solar power system ( SSPS ) for large scale stable power supply
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
U K C anada G erm any U S A Japan
heat ratio
Fig. Share of heat in residential energy demand
How to satisfy residential heat demand
1.Passive use of solar powerex. Passive house in Germany
2. Active use of solar powerintroduction of solar heater,etc.
3. Utilization of ambient energy resourcesas low temp. heat source of heat pump
P0 Heat demand D
Ph
αe COP low temp.ambient energy sources
D =α・COP・P (1)
Energy gain from ambient energy sources
F = P0-Ph = ( 1/αh - 1/ αe・COP ) (2)
Utilization of low temp. geoheat in residential sector
Primary E αh
conversion tosecondary E
powergeneration
heatpump
Ambient energy sources
Conditions: 1) large heat capacity2) available almost everywhere
1. water ponds, rivers, reservoirs, ocean, etc.
2. air3. shallow underground: geoheat
merits and demerits of geoheat
Merits1. Available almost everywhere2. Temperature higher than other ambient
energy resourcesex. 10 deg. in celcius at the depth of 10 m
( in winter, Sapporo, Japan)Demerits: high cost at present
200Japan
9.000France
42.000Switzerland
50,000Germany
500,000USA
total number of houses
Table: Number of houses utilizing geoheat
Potential of low temp. geothermal E- share in residential E, Japan -
1. COP of heat pumpgeothermal: 10 degrees in Celsium ( Sapporo, 10m deep )
supply temp. Theoretical real 30 deg. ( room?) 15 8 ?
50 deg. ( water?) 8 6 ?2. Availability of low temp. geothermal ( potential )
Share in primary energy in Japanresidential
commercial totalCOP=5 3.7 % 2.5 %
6.2 %COP=10( heating) 4.3 3.0 7.3
Photo-voltaics
Magne-tron Rectenna
DC power Micro wave PowerOutput
Laseroscillator
Solarcells
Laser PowerOutput
Fig. Two types of Space Solar Power System ( SSPS )
Merits and demerits of SSPS
Merits1. Stable power supply ( little output
changeability )2. Large scale power generation possibleDemerits1. High costs
Reforestation
CO2
Sequestration
Nuclear Power
OtherRenew. Energy
Photovoltaics
Fuel Switching
Energy Saving
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15
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25
2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100Year
Car
bon
emis
sion
s an
d re
duct
ions
(GtC
/yr)
Energy SavingFuel SwitchingPhotovoltaicsOther Renewable EnergyNuclear PowerCO2 SequestrationReforestationNet CO2 Emission
among Fossil Fuels
Net Carbon Emissionsin 550ppmv Case
Net Carbon Emissionsin Reference Case
Technological Options for 550 Technological Options for 550 ppmvppmv StabilizationStabilization
CO2 Capture and Storage (CCS)
Role of CCS
1. Fossil fuels now occupy about 87% of the worldprimary energy. We need the technology to reduce CO2 emissionin the air while utilizing fossil fuels.
use of CCS2. CCS is not new but comprised of known technologies, therefore
easily put into practice. CO2 capture: separation of CO2 from natural gas CO2 storage: CO2 for enhanced oil recovery ( EOR)
3. CCS has a considerably large potential in reduction of CO2 emission.
→ CCS is a technology to be utilized as the bridge between the present society and the future decarbonized society
Present Activities of CCSred letters: being planned
SNOVHIT
SLEIPNER
IN SALAH
ORCWEYBURNMILLER
GORGON
Source: PaulFreund’s Presentation in RITE’s workshop
Potential of Underground Storage of CO2
Acquifer 8,000 Gt
Depleted oil / gas fields 1,000
Adsorption on deep coal mines 300
emission of CO2 in the world 24 / yearTotal reduction in CO2 emission within 21st century to achieve 550 ppm 1,000 – 3,000
Summary (1)1. Decarbonization of primary energy is a “must” in the long
run.2. Nuclear power is indispensable in the future decarbonized
society. 3. Wind power and photovoltaics which outputs are
changeable with time have high external costs when connected to the grid.
Therefore their capacity should be limited, compared with the demand size of the grid.
4. Utilization of various types of ambient energy sources including geoheat should be promoted.