Compressed Hydrogen System Pressure Selection - Determining the Optimum Hydrogen Fueling Pressure 2007-01-0695

Interest in the hydrogen economy is growing rapidly on the world stage and the market for hydrogen fueling has the potential to become significant. Hydrogen storage onboard the vehicle is one of the challenges facing station and vehicle designers. The current leading candidate for onboard storage of hydrogen fuel is high pressure gaseous storage. At present, hydrogen is typically stored at a fueling system pressure of 35 MPa in high pressure storage tanks in the vehicles. There is currently some movement to go from 35 MPa to 70 MPa. Fueling of hydrogen vehicles must be accomplished in an acceptably safe and economically viable manner.

This paper explores the benefits and costs of various pressure levels, 25 MPa, 35 MPa, 50 MPa and 70 MPa, and identifies which system pressure levels are most advantageous to station providers, OEMs, and ultimately to the consumers in both the development scenario, and the eventual mass production of vehicles. We will present the results of analytical models that help us to understand the benefits and costs of various system pressures in the next generation of hydrogen fueling stations and vehicles. There exists a dichotomy in the needs of the various stakeholders in the hydrogen economy value chain. The results of our model can be used to guide understanding of this dichotomy and can be useful in determining the optimum fueling system pressure for future consumers.