Integrated Wind-Hydrogen Systems for Wind Parks

1. Integrated Wind-Hydrogen Systems for Wind Parks E. Varkaraki, N. Lymberopoulos, E. Zoulias, E. Kalyvas , C. Christodoulou, P. Vionis, P. Chaviaropoulos

2. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ OUTLINE OF THE PRESENTATION • System description • Hydrogen generation section • Hydrogen compressor & Filling station • Metal hydride tanks • Auxiliaries • Power and Control • Results and Discussion • Conclusions

3. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ SYSTEM DESCRIPTION • 500 kW gearless, synchronous, multipole Enercon E-40 • 25 kW alkaline electrolyser, 5 Nm3/h H2 at 20 bar • One-stage hydrogen compressor up to 220 bar • Filling station for high pressure cylinders, 120 Nm3 H2 • Metal hydride tanks, 42 Nm3 H2 • Water chiller and closed cooling circuit • Instrument air compressor • Power board • Control and monitoring section based on PLC • Developed in the frame of the EU project RES2H2 (FP5)

4. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ SYSTEM DESCRIPTION

5. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ HYDROGEN GENERATION SECTION Casale Chemicals SA, Switzerland Alkaline electrolyser 25 kW Power operating range: 20-100% DC operation: 0 - 300 A, 0 - 120 V H2 production: 0.45 kg/h (5 Nm3/h) H2 purity: 99.98%v. (after purification) Demineralised water consumption 4.1 l/h Electrolyte: KOH solution 30%w.

6. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ HYDROGEN COMPRESSOR & FILLING STATION PDC Machines Inc., USA Single-stage hydrogen compressor Triple metal diaphragm Inlet pressure: 10 – 18 bar Inlet temperature: 30 - 40C Outlet pressure: 220 bar 5 Nm3/h at 14bar/40C inlet Buffer: 360 L volume Filling station: 10.7 kg H2 (120 Nm3)

7. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ METAL HYDRIDE TANKS FIT, Cyprus & Labtech SA, Bulgaria 6 Metal Hydride tanks Metal alloy: La0.75Ce0.25Ni5 Total hydrogen capacity: 3.78 kg H2 (42 Nm3) Total weight: 564 kg Mass specific H2 capacity: 1.28 %w (alloy) 0.66 %w (MHT) Hot water boiler 4 kW

8. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ AUXILIARIES WATER CHILLER Cooling water in closed circuit Mean electrical power requirement: 1.5 kW INSTRUMENT AIR COMPRESSOR Pneumatic valve actuation Mean electrical power requirement: 0.2 kW NITROGEN Inertisation of electrolyser and hydrogen circuit

9. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ POWER and CONTROL

10. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ RESULTS and DISCUSSION Electrolyser operation 29.12.05

11. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ RESULTS and DISCUSSION Electrolyser operation DC current measurement, 1 kHz DC current applied: 120 A AC/DC conversion efficiency 85-90% at full power 70-75% at 20% of full capacity

12. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ RESULTS and DISCUSSION Electrolyser operation Variable power input

13. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ RESULTS and DISCUSSION Electrolyser operation Protective polarisation Mean values: DC current: 2.5 A DC voltage: 61 V DC power: 0.15 kW AC power: 0.35 kW • Protective polarisation applied for 27 weeks consumes 1.6 MWh • NO protective polarisation thanks to activated electrodes!

14. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ RESULTS and DISCUSSION Electrolyser operation Stack efficiency: 70-80% (HHV) AC power efficiency: 55-65% (HHV)

15. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ RESULTS and DISCUSSION Electrolyser operation filling the buffer At 1:30 start compressor filling one HP cylinder Overall electrical efficiency from AC power to compressed H2: 50% (HHV)

16. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ RESULTS and DISCUSSION Metal Hydride Tanks operation Preheating phase Winter conditions 4 kW boiler operating 2 hours P mht: 18 bar

17. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ RESULTS and DISCUSSION • Several lessons learned from the realisation of the plant until now: • Interfacing of the various units is key, in relation to hydrogen flow, electricity • and information flow • - Minimisation of buffer tank volume • - Transportation and installation issues in remote areas with poor access • - PLC based control system is safer but less flexible than PC based • Protection of hardware from nature’s elements, theft and even wild animals • Special care for the integration of auxiliaries, vital for safe operation

18. INTEGRATED WIND-HYDROGEN SYSTEMS FOR WIND PARKS _____________________________________________________ CONCLUSIONS • The wind-hydrogen system installed at the wind park of CRES operates well • System efficiency from AC power to compressed hydrogen fuel: 50% (HHV) • Important margins for efficiency increase • power electronics of the electrolyser • wind turbine – electrolyser interface

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