FLEXIBILITY FROM HEAT FOR POWER SYSTEMS
- FUTURE APPLICATIONS FOR CHP AND P2H
Christine Brandstätt, M.Sc.
July 15th 2014, University of Hamburg
image source: www.infoniac.com
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AGENDA
 Introduction
 What is CHP and P2H?
 What flex ibility for pow er s y s tem s can com e from heat?
 How does that com pare to electricity s torage and gas options ?
 S um m ary and Conclus ion
© Fraunhofer
AGENDA
 Introduction
 What is CHP and P2H?
 What flex ibility for pow er s y s tem s can com e from heat?
 How does that com pare to electricity s torage and gas options ?
 S um m ary and Conclus ion
© Fraunhofer
Christine Brandstätt
Education & Career
 Research Associate at Fraunhofer IFAM, Energy Systems Analysis
and at Jacobs University Bremen
 Research Associate at Bremer Energie Institut
 Master in Management and Engineering of Environment and Energy
at Politecnic University of Madrid, École des Mines Nantes and
Royal Institute of Technology, Stockholm
 Bachelor in Industrial Engineering / Environmental Planning
at Environmental Campus of the University of Applied Sciences, Trier
Current Res earch
 Multi-Grid-Storage: power system flexibility from heat and gas links
 Electricity Network Regulation: network charging in distribution systems
with renewable generation
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Fraunhofer IFAM, Energy Systems Analysis
Ins titute for Manufacturing Technology and Adv anced Materials
 components and materials for energy applications
 heat and electricity storage
 electric mobility
 …
Energy S y s tem s Analy s is
 efficient and renewable supply of heat and electricity
 energy efficiency in buildings and manufacturing
 regulatory framework for energy markets and networks
 climate and energy supply concepts
 …
We offer internships, student jobs and supervision of study projects or
Bachelor & Master theses as well as PhD Projects.
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AGENDA
 Introduction
 What is CHP and P2H?
 What flex ibility for pow er s y s tem s can com e from heat?
 How does that com pare to electricity s torage and gas options ?
 S um m ary and Conclus ion
© Fraunhofer
links between electricity and heat supply
electricity s upply
fuel
combined heat and
power (CHP) plant
electric
boiler
heat s upply
© Fraunhofer
heat
pump
ambient
heat
Electric Heat Pump
 moves heat from a lower to a
higher temperature level
 provides heating and cooling
 consumes electricity for
compression of the heating/
cooling fluid
 conversion efficiency: 2 – 5
 high initial investment
© Fraunhofer
image source: daviddarling.info
Electric Boiler
 heats water in a tank via electric
heating elements instead of a
gas burner
 consumes electricity directly
for the heating process
 conversion efficiency: almost 1
 low initial investment
image source: ctadsonline.com
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Combined Heat and Power Plant
 generates heat and electricity at
the same time
 uses the waste heat from an
engine or turbine
 conversion efficiency: almost 1
(varying relation between
electricity and heat)
 high initial investment
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Thermal Store
 stores heat over time
 can continuosly take in and
release heat
 heat losses decrease with surface
and insulation
 efficiency depends on storage
duration
 low initial investment
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image source: heatingsolutions.biz
AGENDA
 Introduction
 What is CHP and P2H?
 What flex ibility for pow er s y s tem s can com e from heat?
 How does that com pare to electricity s torage and gas options ?
 S um m ary and Conclus ion
© Fraunhofer
Why flexibility is needed: future electricity supply
 electricity supply will be based on renewable energy sources (RES),
mainly wind power and photovoltaics
electricity supply in 2030
RES feed-in until 2030
Szenario 2030
120
100
80
60
40
20
(20)
1
352
703
1054
1405
1756
2107
2458
2809
3160
3511
3862
4213
4564
4915
5266
5617
5968
6319
6670
7021
7372
7723
8074
8425
-
(40)
(60)
Last
Erzeugung Wind, PV & Laufwasser
Residuallast
 significant differences between availability of RES and the demand for
electricity expected
 high spikes in residual load
© Fraunhofer
Quelle: Krzikalla et al. 2013
Quelle: Krzikalla et al. 2013
GW
Why flexibility is needed: challenges with RES
Electricity S upply
 supply electricity efficiently when wind power and photovoltaics are not
available in sufficient quantity (shortage)
 reduce supply from other sources when wind power and photovoltaics
are available in abundance (surplus)
Heat S upply
 reduce heat demand (especially for space heating)
 supply remaining heat demand in a sustainable way
(renewable electricity vs. fossil gas)
 both is addressed by extensive use of CHP
 best effect with electric conversion efficiency
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How much flexibility is needed (tech.)
 pos. residual load
(shortage)
80
Residual load [GW]
60
 163 TWh/a
40
 6.384 h/a
20
163 TWh
 max. 71 GW
0
-20
0
1000 2000 3000 4000 5000 6000 7000 8000
-40
46 TWh
 neg. residual load
(surplus)
-60
 46 TWh/a
-80
 2.286 h/a
-100
annual hours
 max. -84 GW
 ‚surpluses‘ to take into storage occur more and more often
 ‚shortages‘ to supply from storage dominate
© Fraunhofer
Quelle: Krzikalla et al. 2013
ordered residual load in 2030
How much flexibility is needed (econ.)
extreme electricity wholesale prices in Germany and Denmark 2011 and 2012
 prices above 75 € / MWh only in several hundred (of over 8000) hours
(good conditions for CHP, + feed-in support)
 negative prices in less than 50 hours
(good conditions for P2H, + taxes and surcharges)
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Flexibility from CHP and P2H and other sources
RES electricity s urplus
Heat pump
Electric Boiler
Heat
flexible demand
displaced heat
Heat
(virtual energy flow)
Gas Boiler
displaced gas
other storage options
Heat Network
(virtual energy flow)
CHP Plant
RES electricity s hortage
© Fraunhofer
flexible generation
Flexible operation of CHP and P2H
12.000
7,00
6,00
10.000
capacity [kW]
8.000
4,00
6.000
3,00
2,00
4.000
1,00
2.000
0,00
0
© Fraunhofer
-1,00
Versorgung EK
Versorgung KWK
Versorgung Speicher
Einspeicherung EK
Einspeicherung KWK
Wärmeerzeugung GK
Wärmelast
Strompreis
electricity price [ct/kWh]
5,00
IFAM study on flexibility from heat
for the German Renewable Energy
Federation & the Association for Efficiency
in Heating, Cooling and CHP
together with Wolfgang Schulz
 modelling of CHP heat supply
 economic analysis of heat and electricity
driven CHP operation
 optimization of heat storage volume
 analysis of a combination with heat
pumps and electric boilers
 flexibility potential from heat supply
© Fraunhofer
Modelling of CHP heat supply
 CHP production influenced by
 heat demand
multiple
dwelling
reg. heat
network
large heat
network
 dimensioning
electr. capacity (kW )
1
20
1.000
88.000 (100.000)
 energy prices
therm. capacity (kW )
5,7
32,7
1.122
80.000
 support schemes
elektr. efficiency (η )
15%
33%
41%
46,3% (52,6%)
therm. efficiency (η )
81%
54%
46%
42,1%
 present and future data
el
th
el
th
100%
Heat load
detached
house
80%
60%
40%
20%
0%
0
© Fraunhofer
2.000
4.000
6.000
annual hours
8.000
Analysis of electricity and heat driven operation of CHP
 lesser full load hours in electricity driven than in heat driven operation
 high dimensioning (capacity high compared to average heat
demand):
2.938 full load hours per year instead of 4.000
 low dimensioning (capacity low compared to average heat demand):
4.418 full load hours per year instead of 6.000
 higher electricity revenue (support scheme + exchange prices) required to
recover investment assuming constant heat prices
 additional cost for flexibility from CHP
© Fraunhofer
Analysis of electricity and heat driven operation of CHP
 electricity cost with lesser full load hours for different CHP sizes
electricity generation cos t €/MWh
500
400
300
1 kW-BHKW
20 kW-BHKW
200
1 MW-BHKW
GuD (KWK-Betrieb)
100
0
0
1.000
2.000
3.000
4.000
Annual utilization h/a
 lesser cost increase for larger plants
© Fraunhofer
5.000
6.000
Optimization of heat storage: potential
CHP utilization h/a
 Heat storage can partially recover ‚lost‘ full load hours
5.200
4.800
ursprünglich 4000 Vh/a
4.400
ursprünglich 6000 Vh/a
4.000
3.600
3.200
2.800
0
© Fraunhofer
200
400
600
800
1.000
heat s torage v olum e m ³
1.200
1.400
1.600
Optimization of heat storage: cost
 Specific investment decreases with volume
decentral heat storage
large scale heat storage
s pec. Inv es tm ent €/m ³
s pec. inv es tm ent €/m ³
1.500
1.250
1.000
750
500
250
0
0
5
10
15
heat s torage v olum e m ³
© Fraunhofer
20
1.400
1.200
1.000
800
600
400
200
0
0
10.000 20.000 30.000 40.000 50.000
heat s torage v olum e m ³
Optimization of heat storage
increas e in CHP utilization h/a
 optimal storage size depends on cost and recovered full load hours:
(for the example of 1 MW CHP) between 200 and 400 m3
© Fraunhofer
700
600
387 m³ / 12 h over
24,3 €/(kWel*a)
500
400
300
200
200 m³ / 6,2 h over
15,3 €/(kWel*a)
100 m³ / 3,1 h over
9,5 €/(kWel*a)
100
0
0
20
40
60
80
annual cos t of heat s tore according to el. CHP capacity
€/(kWel *a)
Combination with P2H
 supplying heat from P2H in hours with significant surplus
 reduces CHP full load hours
 requires higher electricity revenues (if heat revenue remains constant)
CHP full load hours per y ear [h/a]
only CHP
CHP with P2H
required rev enue for CHP electricity [ct/kWh]
only CHP
CHP with P2H
 moderate increase of required revenue only for larger plants
© Fraunhofer
Combination with heat pumps
 cost of heat generation through heat pumps depend on utilization
cost of heat supply (ct/kWh)
35
30
25
20
"1 kW-Fall"
15
"20 kW-Fall"
"1 MW (6000 h/a)-Fall"
10
"1 MW (4000h/a)-Fall"
5
0
0
500 1.000 1.500 2.000 2.500
heat pump utilization (h/a)
 lesser effect of reduced full load hours for larger heat pumps
© Fraunhofer
Flexibility potential of P2H and CHP
80
Res idual load 2030 (GW)
60
40
20
0
-20
0
CHP
2.000
4.000
6.000
8.000
-40
-60
P2H
-80
-100
hours per y ear (h)
 CHP and P2H together can provide a large share of the flexibility
needed in the future (2030)
© Fraunhofer
AGENDA
 Introduction
 What is CHP and P2H?
 What flex ibility for pow er s y s tem s can com e from heat?
 How does that com pare to electricity s torage and gas options ?
 S um m ary and Conclus ion
© Fraunhofer
Flexibility from CHP and P2H and other sources
RES electricity s urplus
Heat pump
Electric Boiler
Heat
flexible demand
displaced heat
Heat
(virtual energy flow)
Gas Boiler
displaced gas
other storage options
Heat Network
(virtual energy flow)
CHP Plant
RES electricity s hortage
© Fraunhofer
flexible generation
© Fraunhofer
Elektrokessel
Druckluftspeicher
Pumpspeicher
Redox-Flow Batterie
175%
Anteil Strom heute
Anteil Wärme heute
Anteil Strom in Zukunft
Anteil Wärme in Zukunft
worst case
best case
PEM El. + biol. Methan.
PEM El. ohne Methan.
alkal. El. + kat. Methan.
alkal. El + kat. Methan.
(Wärmenutzung)
alkal. El. + biol. Methan.
SO El. + kat. Methan.
SO El. + kat. Methan.
(Wärmenutzung)
150%
alkal. El. ohne Methan.
200%
SO El. + biol. Methan.
225%
SO El. ohne Methan.
el. boiler
+ CHP
heat pump
+ CHP
Li-Ionen Batterie
Wärmepumpe
(Umgebungsluft
Wärmepumpe
(Bodenkollektor)
ex ergy at electricity releas e
(100% at intake)
exergy balance of shifting el. from surplus to shortage
125%
100%
75%
50%
25%
0%
© Fraunhofer
Elektrokessel
Li-Ionen Batterie
PEM El. ohne Methan.
-10
-20
PEM El. + biol. Methan.
CHP
SO El. + kat. Methan.
10
SO El. + kat. Methan.
(Wärmenutzung)
20
alkal. El. + kat. Methan.
30
alkal. El + kat. Methan.
(Wärmenutzung)
best case
SO El. + biol. Methan.
worst case
Pumpspeicher
Redox-Flow Batterie
ct/kWh
40
alkal. El. + biol. Methan.
heat pump
+ CHP
Druckluftspeicher
in Zukunft
SO El. ohne Methan.
0
Wärmepumpe
(Bodenkollektor)
heute
Wärmepumpe
(Umgebungsluft)
alkal. El. ohne Methan.
el. boiler
+ CHP
S torage / s hifting cos t
cost of shifting electricity from surplus to shortage
€/kWh
4,00
3,50
3,00
2,50
2,00
1,50
1,00
0,50
0,00
AGENDA
 Introduction
 What is CHP and P2H?
 What flex ibility for pow er s y s tem s can com e from heat?
 How does that com pare to electricity s torage and gas options ?
 S um m ary and Conclus ion
© Fraunhofer
Conslusion
 future electricity supply is likely to require additional flexibility
 CHP and P2H (among other options) can provide flexibility
 provision of flexibility requires
 alternative dimensioning (peak supply, heat storage)
 additional revenue options (electricity prices, support schemes)
 larger systems can provide flexibility more efficiently and at lower cost
© Fraunhofer
THANK YOU FOR YOUR TIME AND ATTENTION.
Feel free to ask questions.
Christine Brandstätt M.Sc., Fraunhofer IFAM, Energy Systems Analysis
christine.brandstaett@ifam.fraunhofer.de, +49 (0) 421 2246 - 7027
image source: www.infoniac.com
© Fraunhofer