Question

Consider a fuel cell vehicle. The vehicle draws 30 kW of power at 60 mph and is 40% efficient at rated power. (It converted 40% of the energy stored in the hydrogen fuel to electric power.) You are asked to size the fuel cell system so that a driver can go at least 300 miles at 60 mph before refueling. Specify the minimum volume and mass requirements for the fuel cell system (fuel cell + fuel tank) given the following information:

Fuel cell power density: 1 kW/L, 500 W/kg

Fuel tank energy density (compressed hydrogen): 4 MJ/L, 8 MJ/kg