The hydraulic hydro energy storage system can store a whole day of the electricity of a country like Germany. It uses only conventional turbine techniques and has a very low land usage. The price per kWh is an order below known systems like pumped hydro power. But see the details!

1. Large Energy Storage System Eduard Heindl Hochschule Furtwangen University, Germany

2. Renewable Energy needs storage wind 60% solar 40% supply change source: Lueder von Bremen, EWEC 2009 storage for up to seven days required!

3. Electicity: Daily Production Base load: coal, nuclear daily production: 1600GWh Problem: how to use this energy 70GW 280GW Hydro Storage capacity in Germany: 40GWh 0h midnight 24h time „ priceless energie“ solar power, wind power Consumption in Germany 12h high noon

5. 1km

6. Think Big! 1km 500m 1700GWh

8. Construction 1km mine shaft base tunnel, water intake 1. tunnel 1km blast hole construction road deep well drilling plant

9. Construction work 1km 1. tunnel lower saw mill wire saw upper saw mill blast hole construction road

10. Diamond wire sawing Surface 1. Tunnel traction cut surface Diamondwire saw rock drilling holes r

11. Diamond wire sawing surface 1. tunnel traction Diamond wire saw rock drilling holes r cut surface

12. Baseplate seperation base-tunnel 2. tunnel traktion sawing string rock drilling holes r cutted rock remaining rock top view!

14. Cutting completed 1km 1. tunnel 2. tunnel construction road the wall and the floor of the cylinder are separated from the surrounding rock

16. Energy Storage Capacity h=r D=2r l=2r Generated surface: M = 2 * π * r * l = 4 * π * r² (1) Real density ρ 2 = ρ 1 – ρ 3 (2) Potential energy in gravitation field E = g * m * h (3) Real mass of cylinder m = π * r² * 2 h * ρ 2 (4) Eq. 4 and eq. 3 using h = r results in: E = g * π * r² * 2 * r * ρ 2 * r (5) Eq. 5 condensed: E = 2 π g ρ 2 * r 4 the power V=4πr³

17. 500 1.700 Beispiel Daily electrical power production in Germany Energy storage capacity depends on the Radius r Example Source: www.eia.doe.gov/cneaf/electricity/epm/table1_1.html Daily electrical power production in USA 800

19. Sealing the Walls rock mass piston 1. tunnel platform sealed wall support column sealing water under pressure Saw line

20. Closing the Cracks rock mass piston piston 1. tunnel water under pressure wall with sealant ad sealant seal crack

21. Complete the Sealing rock mass piston piston 1. tunnel water under pressure wall with sealant ad sealing seal crack

22. Sealing rock mass piston pin joint with sensor seal steel podest water pressure

28. pump storage power station 0,39 500 100 1.000 example system Price per kWh storage volume (excluding the energy converter) price system radius [m]

29. 0,39 500 100 1.000 day week month year 200€/kW pump storage power station example system system radius [m] price Price per kWh storage volume (using different converters, 200€/kW)

30. Calculation 157 € /m 1 000 Drilling 821 Total 3 € /m 1 000 Sealing 157 € /m² 100 Seal shield 39 € /m² 10 Sawing 464 € /m 50 000 Tunnel Mio € unit cost per Building

31. Calculation 2 861 Total 2 040 € /kWh (T=7d) 200 Pumps and Generators 821 Storage system Mio € Cost

32. Return on Investment DRAFT! Assumption: there are 100 days (2,400h) where the power could be bought with a mean price of 20€/MWh and there are 2400h where it could be sold for 70€/MWh, the other times of the year, there is no activity. The conversion efficiency is 70% (worst case ) 710 Total (Q=70%) 1 200 € /MWh (T=100d) 70 Power sell Per year 490 € /MWh (T=100d) 20 Power buy per year Mio € Turnover

38. Thank you for your interest! Questions? eduard-heindl.de/energy-storage