Costs hydrogen storage methods

Relatively high cost as compared with gaseous and liquid hydrogen storage methods. 

Practical use of hydrogen in vehicles may never happen until there is a better method to store hydrogen, especially since onboard reforming of hydrogen at a reasonable cost may not be a possibility. The U.S. Department of Energy has worked with the auto industry and has ranked the options for hydrogen storage. The best candidate so far is compressed gas at pressures of about 700 bar. While not an ideal solution, it is probably marketable. 

Many options exist for the enhancement of the thermal properties of reversible hydrogen storage materials. The optimum method must be chosen based on the optimization of the total system energy densities, hydrogen uptake and delivery performance, and cost targets. 

Once the number of compressors is determined, the work requirement (kW) for these compressors is found using Equation (10). This work requirement, or necessary compressor size, is used to determine the total energy requirement for the compressor, based on the capacity factor. It also is used to determine the capital cost of the compressor using the same method as the compressors in hydrogen storage. 

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