Integration of renewables through thermal load flexibility by price driven heat pumps ThermSpe4EE Thermal storage for renewable integration

Transcription

1 Integration of renewables through thermal load flexibility by price driven heat pumps ThermSpe4EE Thermal storage for renewable integration Cleantech Community Forum Lueven May Dipl.-Wirtsch.-Ing. Stephan Röhrenbeck W.H. Wellßow Chair for Energy Systems and Energy Management

2 Structure Renewable energy generation Installed capacities Chronical sequence of feed-in Final energy demand of private households Price based heat pump control Background Modeling and design criteria Energy shift and load shift potential Conclusion and outlook

3 Installed power capacity Installed power capacity of renewable energy in Germany in GW Hydro Biomass Wind (onshore) Wind (offshore) Photovoltaic Installed renewable power capacity - Percentage in different voltage levels EHV EHV/HV HV HV/MV MV MV/LV LV Photovoltaic 0% 5% 2% Photovoltaic 0% 5% 2% Wind 0% 11% 1% 33% 43% % 32% % Biomass 3% 13% Hydro 33% % 8% 0%5% 4% 3% 15% 3% 0% 9% 11% % 0 79% 57% Source: Data from Working Groups on Renewable Energies Statistic (BMU) Source: BNetzA

4 Load and production (July ) - Germany Change from negative to positive residual load in the control area of TenneT Control area TenneT Germany Source: agora-energiewende, entso-e

5 Load and production (December ) - Germany Negative residual load for more than 24 hours in the control area of TenneT Control area TenneT Germany Source: agora-energiewende, entso-e

6 Final energy demand Final energy demand of private households (636 TWh) Room heating Domestic hot water Other heat Air conditioning Other cooling Mechanical ernergy Information and communication Lighting 1,7% 4,7% 0,7% 3,6% 0,2% 6,2% 14,4% 68,5% Source: UBA Germany,2015

7 System overview Low voltage grid Building Gebäude Residual load of the building Current room temperature Target room temperature P-29P-33 House Plot Street Network Station Distribution Line Service Connection Line EHP electricity consumption Control signal / Inlet temperature Control signal P-30 P-43 DHW-load Reat time ambient temperature Controller of the Heat Pump Heating and DHW requirement forecast Energy supplier Dynamic price structure Load forecast Variable electricity price Weather forecast à Optimal heat pump operation schedule based on variable electricity tariffs and best COP Buffer storage Buffer storage temperatures (3-levels)

8 Methodology Power to Heat with innovative storage mechanisms and adequate control strategies of electric heat pumps New heating systems (Electric heat pumps) and additional storage systems Innovative control concepts for electric heat pumps Optimal operation of the heat pump-storage-system Cost-savings Grid relieve effect Contribution to active power balancing

9 Building model Modeling Heating energy demand Domestic hot water demand Electric heat pump model Variable speed Fixed speed Storage model Buffer storage system Building component activation Dynamic electricity price Market based price with four levels Artificial price spread

10 Heating days Price signal Hours per day Price level 1 Price level 2 Price level 3 Price level 4

11 Heating power kw Price signal (cent/kwh) Operational schedule Operation schedule (SFH-E, 1000 liter, 13 kw variable speed, day 80) Planned shedule HP use (simulation) Price signal Time (1/4 hour)

12 Average el. load shift [kw] Average el. load shift [kw] Average load shift SFH-1960, 80%, 1h SFH-1960, 120%, 6h Ambient temperature [ C] Solar radiation [W/m 2 ] Solar radiation [W/m 2 ] Ambient temperature [ C]

13 shifted energy [kwh/year] Energetic Shift Potential Shift of 1/3 of yearly heating demand Energy amount mostly dependend on heating load Minor influence of price signal Huge influence of installed power and storage capacity thermal electrical Heat pump storage combination

14 energy costs [ /year] Comparison of Costs Economically feasible only for some combinations Tariff has impact Change of COP has the biggest influence Effects of changing COP bigger for low energy buildings heat driven price driven Heat pump storage combination

15 Conclusions Huge load shift potential of thermal energy Also huge load shift potential on electrical side Optimal storage time 6 hours (T a = 2 C) But: depending on tariff Load shift potential in most cases not economical feasible yet Only small correlation with PV-feed- in Almost no relieving impact on LV-distribution grids HPs have simultaneity factor up to 1 High penetration levels of heat pumps lead to line overloads

16 Suitable Tariff has to be found Outlook Correlation with wind-feed-in has to be examined Improvement of annual COP Storage technology (Phase change material) Enhancement of optimization algorithm