Net energy analysis of hydrogen storage options

Hydrogen storage is critical for developing viable hydrogen vehicles. This paper compares compressed hydrogen, cryogenic hydrogen and metal hydride (Mg and FeTi) options using net energy analysis. A simulation of an Indian vehicle with an urban drive cycle using a fuel cell stack is carried out to determine the total hydrogen required per km of travel. ergy analysis is carried out considering the energy requirements of the storage device and the energy required to produce and store the hydrogen. From net energy analysis compressed hydrogen is the preferred option. The direct energy requirement is more than 55% for magnesium hydride as compared to compressed hydrogen due to the combined effect of increase in weight and higher heat of desorption. ition to volumetric and gravimetric storage density, it is felt that net energy analysis should be also included as an additional criteria for evaluating any storage option. For metal hydride storage the net energy required to produce the tank should be minimum. This could be used as a selection criterion to design an optimum metal hydride storage. The performance of other materials like porous carbon, carbon nanotubes and hybrids can be evaluated using net energy analysis.