It takes between 50 and 60 kWh of electricity to make a kilogram of hydrogen. That energy requirement includes ancillary equipment such as pumps and coolers. However, there can be significant additional energy requirements to compress hydrogen to high pressures (e.g., light duty vehicles take up to 10,000 psi [700 bar] hydrogen). Energy for compression adds another 1.5-6 KWh of energy depending on the efficiency and compression level.

Hydrogen can also be liquefied for more efficient bulk transportation over long distances, which can add 8.3-12 kWh/kg to the energy requirement beyond the energy used to make the hydrogen.

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