Low Total Cost of Hydrogen by Exploiting Off Shore Wind and PEM Electrolysis Synergies

The use of hydrogen as an energy carrier for stationary and automotive applications is increasingly being realized. Traditionally, hydrogen use has been held back due to large capital costs for the fuel cells, as well as high operating costs due to the price of hydrogen. Great strides in PEM fuel cell technology have greatly reduced the former, while the drastic reduction in renewable energy costs has the potential of lowering the latter. Currently, generating hydrogen by electrolysis from energy supplied by the grid is simply too expensive. We aim to directly integrate PEM water electrolyzers with offshore wind turbines to produce green hydrogen. Coupling the electrolyzer with the wind turbine, which is also called offshore wind electrolysis OSWE, enables direct operation from the windmill’s DC power and transmission of hydrogen at high to moderate pressures to shore, thus significantly lowering the cost and improving the efficiency of both unit operations, while providing hydrogen storage. We developed rigorous models for producing hydrogen via OSWE and the levelized costs of both energy and hydrogen were calculated. These models demonstrated that the price of hydrogen produced by OSWE could be as low as $2.08/kg H2, which is close to hydrogen produced from steam methane reforming SMR. The models also showed that the levelized cost of energy for hydrogen production and transportation to shore could be lower than for electricity transmission from offshore wind farms. We will build a subMW stack and physically integrate it with an offshore wind turbine. We will determine different system process and instrumentation needs for the OSWE and design power electronics and control of wind turbine for electrolyzer integration. We will determine the impact of impurities in seawater on PEM electrolyzer performance and come up with viable solution to obtain purified water for electrolysis. We will evaluate the OSWE at different operating conditions and intermittency. The OSWE will enable production of green hydrogen at a price of $2/kg H2, similar to SMR. This may significantly enhance the adoption and application of renewable hydrogen in many industrial sectors. Therefore, it will substantially reduce CO2 emissions in the United States and open up new markets for clean hydrogen.