Refueling-station costs for metal hydride storage tanks on board hydrogen fuel cell vehicles.

Refueling costs account for much of the fuel cost for light-duty hydrogen fuel-cell electric vehicles. We estimate cost savings for hydrogen dispensing if metal hydride (MH) storage tanks are used on board instead of 700-bar tanks. We consider a low-temperature, low-enthalpy scenario and a high-temperature, high-enthalpy scenario to bracket the design space. The refueling costs are insensitive to most uncertainties. Uncertainties associated with the cooling duty, coolant pump pressure, heat exchanger (HX) fan, and HX operating time have little effect on cost. The largest sensitivities are to tank pressure and station labor. The cost of a full-service attendant, if the refueling interconnect were to prevent self-service, is the single largest cost uncertainty. MH scenarios achieve $0.71–$0.75/kg-H 2 savings by reducing compressor costs without incurring the cryogenics costs associated with cold-storage alternatives. Practical refueling station considerations are likely to affect the choice of the MH and tank design. Image 1 • Metal hydride storage tanks on board fuel cell vehicles reduce modeled fueling costs. • Costs were lower compared to 700-bar tanks because of lower compression costs. • Savings were insensitive to uncertainties other than station labor and tank pressure. • A key question is whether self-service is possible despite required coolant lines. [ABSTRACT FROM AUTHOR]