1. The German "Energiewende" Electricity Solely From Renewable Resources?

2. Contents  Introduction  Boundary conditions and presumptions  Simulation  Results  Conclusions

3. Introduction  CO 2 causes Greenhouse effect  Germany is one of the biggest CO 2 emittents  Countermeasure: „Energiewende“

4. Annual energy consumtion in Germany  1202 TWh for heating  718 TWh for fuels  600 TWh electrical energy

5. Present sources for electrical energy  Total average power: 70.0 GW  Total energy: 600 TWh

6. Renewable electrical energy  Annual total energy: 157.4 TWh

7. Boundary conditions and presumptions  Presumptions:  Continuously increasing share of renewable energy  Chemical energy storage by H 2 via electrolysis 2 H 2 O -> O 2 + 2 H 2,  h = +571,8 kJ/mol H 2 tank Electrolyser Gas turbine

8. Boundary conditions and presumptions  Leading questions:  Optimum layout of photovoltaics, wind and (bio mass + water power)?  Required peak powers?  Maximum energy storage?  Required power for electrolysers and gas turbines?

9. Boundary conditions and presumptions  Realistic electricity consumption profile  Power: 32 – 94 GW  Total annual energy: 600 TWh Summer Winter Power Time Basic load Average load Basic load Maximum load Maximum load Average load

10. Characteristics of renewables  Water Capacity fully used  Bio mass Ethical problems, only waste should be used  Geothermal energy Small scale  Wind Public resistance  Photovoltaics Expensive, small efficiency

11. Assumptions for weather  Annual number of depressions: 20 (period: 18 ¼ days)  Amplitude sun power: 15 – 100 %  Amplitude wind power: 0 – 100 %  Seasonal distribution of wind power: Between 5 % in June and 12 % in December  Phase shift between maximum sunlight and maximum wind:  /2 = 4 ½ days  Day length: 7 – 17 hrs

12. Simulation with Excel  1 hr per line = 8760 lines for one year  Cosinus interpolation between the curves

13. Simulation of sun power  Present sunpower:  Heigth of sun over horizon (0 during nighttime)  Multiplied with weather factor

14. Simulation of wind power  Present wind power:  Weather factor  Multiplied by seasonal wind factor

15. Overlay of simulation results  Required power  Minus present sun power  Minus present wind power  Minus permanent power Water + Bio mass = 22.8 GW  Equals  Electrolyser power (when negative)  Auxiliary gas power (when positive)

16. Result Optimum shares:  Solar 15 %  Wind > 50 %

17. Required powers  Required reservoir space: 26.5 TWh  Required power: SourcePeak powerExistingUtilisation ratio [GW][GW] (2013) Photovoltaics75.636.013.6% Wind96.733.736.6% Others22.8 100.0% Electrolyser53.50.023.2% Gas standby70.621.017.6%

18. Conclusions  Enough electrical power can be produced by renewable energy  Storage space already exists  Technical bottleneck for the Energiewende: The realisation of high-power electrolysis  Economical bottleneck for the Energiewende: The recovery of the stored energy by gas power (average load less than 18 %)

19. Relevance to Dr. Friedrich?  Total average power: 70.0 GW  Total energy: 600 TWh

20. Happy Birthday! georg@geo-vibe.degeorg@geo-vibe.de - www.geo-vibe.dewww.geo-vibe.de