Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
Seasonal Thermal Storage
State of the Art and Future Aspects
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
H. Kerskes
Institute for Thermodynamic and
Thermal Engineering (ITW)
Universitt Stuttgart
Pfaffenwaldring 6
70550 Stuttgart
Internet: www.itw.uni-stuttgart.de
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
Outline
Small scale seasonal thermal energy storage
for single and multifamily houses
Large scale seasonal thermal energy storage
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
solar assisted districted heating systems
Relevance of seasonal thermal energy storage
state of the art
new developments
future aspects
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
Small solar thermal combisystems
Typical size of solar combisystems
10 -20 m collector area
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
750- 1500 l tank volume
solar fraction 15 30%
market share (Germany)
2000
20 %
20082006
50 %> 50 %
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
Market development of solar thermal systems
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
in Germany (source BSW)
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
12.900.000 m collector area installed in Germany
9.7 GW peak power installed
approx 30 % = 2.9 GW on solar thermal combi systems
typical stagnation time of combisystems 200 h/a
2.9 GW * 200 h/a * 0.3 = 175 GWh/a = 175 000 000 kWh/a of heat
Waste of Heat
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
2.9 GW * 200 h/a * 0.3 = 175 GWh/a = 175 000 000 kWh/a of heat
not used, enough for 100.000 people
Reason: low heat demand in summer, no long term storage capacity
Solution: seasonal heat storage
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
high solar fraction > 50%
large collector areas
30 m to 60 m
large hot water storage tanks
Solarhouse 50+ : the next standard
Small scale seasonal thermal storage
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
large hot water storage tanks
6.000 to 10.000 litres
Quelle: Sonnenhausinstitut e.V.
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
large steel tanks
new buildings: insertion during construction phase
building stock: on site welding of steel tank
State of the Art
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
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17,5 m3 Speicher; Quelle: http://www.jenni.ch/
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
Large hot water storage tanks
cylindrical polymeric tanks
on site fabrication, laminating
New developments
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
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Tank Fa. Haase; Quelle: http://www.ichbin2.de/waermespeicher.html
volumes: 10 - 40 m
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
Large hot water storage tanks
steel frame with polymeric panels
pressure less tank
in situ construction and sealing
cubical shaped tank
space efficient
New developments
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
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space efficient
well fitted to localities
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
modular concepts / ideal for building stock
very flexible in design
easy to install
well insulated (VIP)
Future hot water stores
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
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well insulated (VIP)
perfect temperature stratification
pre fabricated containers
polymeric tank materials
cost efficient by industrial
manufacturing of modules
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
Heat Storage Technologies
storage
thermal thermo chemical
sensibleheat
heat of reaction
latentheat
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
Thermo-chemical heat stores- first developments in adsorption processes
- first approaches with chemical reactions
liquid solid solid-liquid liquid-vapour
water rock melting evaporation
aquifer
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
Small scale seasonal thermal storage
Targets for solar systems:
significant decrease in
storage size, collector size
Solarhouse 50+
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
Quelle: Sonnenhausinstitut e.V.
next improvements
and system costs
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
Small scale seasonal thermal storage
Targets for solar systems:
significant decrease in
storage size, collector size
Solarhouse 50++
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
Adsorption Heat Stores
half of collector area
half of storage volume
and system costs
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
Small scale seasonal thermal storage
Targets for solar systems:
significant decrease in
storage size, collector size
Solarhouse 50 super+
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
Chemical Heat Stores
half of collector area
1/5 of storage volume
and system costs
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
storage energy density factor
Water * 60 kWh/m 1
Advantage of thermo-chemical heat storage
high energy density
almost loss free heat storage
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RHC Workshop on Thermal Energy Storage - February 10, 2011 - Brussels in cooperation with
Water * 60 kWh/m 1
Latent 50 -120 kWh/m 1 2
Adsorption 120 - 180 kWh/m 2 3
Reaction 200 - 600 kWh/m 4 10
* with T = 50 K
disadvantages: high power output difficult
high regeneration temperature (120 180C)
Forschungs- und Testzentrum fr Solaranlagen
Institute for Thermodynamics and Thermal Engineering
Research and Testing Centre for Thermal Solar Systems (TZS)
Potential study - simulation results
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RHC Workshop on
