1. A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems Lars Nesje Grimsmo NTNU Magnus Korpås NTNU Terje Gjengedal NTNU/Statkraft Steffen Møller-Holst SINTEF Materialteknologi A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems

2. Plant overview A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems

3. Principles of water electrolysis A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems PEM Electrolysis H2H2 e-e- O2O2 H+H+ membranecathodeanode H2OH2O cathode:2H + + 2e -  H 2 andoe:H 2 O  2H + + 2e - + ½O 2 H2H2 Alkaline Electrolysis cathode:2 H 2 O + 2e -  H 2 + 2OH - anode: 2OH -  ½O 2 + H 2 O + 2e - electricity + H 2 O  H 2 + ½O 2 e-e- H2OH2O KOH O2O2 H2H2

4. Electrolyser performance A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems

5. Benefits of wind-electrolyser systems A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems Exploitation of wind resources in areas with no electricity infrastructure. Hydrogen from renewables is an environment-friendly fuel. Hydrogen could be used both for transportation and for stationary energy supply. Oxygen as a by-product could be used in e.g. fish farms.

6. Technical challenges A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems No grid connection. Dynamic performance of electrolyser. Start-stop of electrolyser. Need for short-term energy storage (battery, flywheel…). Sizing of electrolyser, wind turbine and hydrogen storage. Design of power converters and control system.

7. Wind conditions in Norway A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems

8. Weibul distribution for a year A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems

9. Normal distribution for a day A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems

10. Simulation case study A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems Input parameters 500 kW wind turbine 3 hydrogen buses Mean wind speed 7 m/s Sizing results 80 kW electrolyser 330 kWh lead-acid battery 3300 kg hydrogen storage tank Component data Investment cost O&M cost Efficiency Wind turbine800 $/kW2 %100 % El. energy storage 350 $/kW 350 $/kWh 4 %70 % a Electrolyser450 $/kW4 %4.5 kWh/Nm 3 Compressor2,000 $/kW4 %0.35 kWh/Nm 3 Hydrogen storage 60 $/Nm 3 2 %100 %

11. Sensitivity of wind speed A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems

12. Sensitivity of lifetime A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems

13. Conclusions and further work A Probabilistic Method for Sizing of Isolated Wind-Electrolyser Systems The method can be used for estimating the required component sizing for a specific hydrogen demand. The method shows good results when compared with chronological simulations. Further work will focus on improved rules for sizing of short-term storage. Further development of the model could include a more accurate representation of electrolyser and power convertes. The sizing priciples will also be used for isolated systems with stationary fuel cell.