Methods of hydrogen storage for standby power units

A case can be made that the energy storage molecule of the future will be hydrogen. Hydrogen is an attractive fuel because it is plentiful and clean. It is found in atomic abundance in water and hydrocarbons, and its only oxidation product is water. The major challenge hydrogen fuel must overcome is the issue of storage. As the distributed energy market grows and looks to hydrogen as a clean fuel for combustion engines and fuel cells, questions loom about which methods of containment will prove to be safest and simplest for storage and delivery of hydrogen. This paper contrasts hydrogen fueling system technologies for standby power applications and allow readers, through a fair comparison, to measure the fit of various technologies for this telecommunications application. Issues such as system cost, operating cost, system volume and weight, start-up time, refueling time, maintenance, safety, environmental impact, and ease-of-use are the characteristics analyzed for the different fueling technologies. These requirements are matched against the specifications for standby electricity generators to quantify the trade-offs among the hydrogen fueling technologies. Two power ranges for the standby power applications will be considered. Small units have power capabilities of 500-1000 Watts, and large units provide power at 50-100 kilowatts. For the small systems, the storage technologies to be compared are liquid hydrogen, compressed hydrogen, reversible metal hydrides, reactive hydrides with water, and carbon nanostructures. The common thread for all of these hydrogen storage systems is that they are all zero emission at the point of use, making them suitable for operation in an enclosed area such as an office. For larger systems the HA will be expanded to include reforming technologies, with the caveat that reformers can only be used in well ventilated areas due to the carbon emissions associated with reforming of hydrocarbon fuels.