Compressed hydrogen storage

Applications are at industrial sites or at H₂ filling stations for mobility services. The storage installation consists of a compressor, a rack of storage vessels and an expander, which can be a simple valve. A typical unit consists of a rack of vessels able to store 500 kg or, equivalently, 16.7 MWh of hydrogen. The capacity of the compressor is typically 50-60 kg/h, or 1.67-2 MW_H₂. For storage up to 200 bar specific cooling is not required. The storage units may either be placed on the H₂ pipeline or in the distribution network. Inlet pressures to the compressor may vary between 1 -70 bar. The volumetric density of hydrogen compressed at 200 bar and 273°C is 15.6 kg/m3 or 520 kWh/m3 (Lower Heating Value).

Investment cost of compressed hydrogen storage consists of major two parts, the costs of the vessels which scale with the amount of hydrogen (kg or MWh) that can be stored, and the cost of the compressor which scale with the maximum flow of hydrogen (kg/h or MW_H2) into the compressor. Here we use MW as the unit of capacity for the installation.