Environmental and Energy Aspects
Fuel Cells applied to Electric Mobility. Part 2: Environmental and Economic Aspects of Hydrogen Mobility

Hydrogen can be produced by steam reforming of hydrogen-rich fuels. This process offers very high energy efficiency, up to 90% (with losses being primarily thermal). However, CO₂ emissions from this process are higher than those from the direct combustion of these fuels. Water electrolysis is the process that, provided the electricity used is carbon-free, yields green hydrogen. The efficiency of electrolysis can reach 85% for large-scale PEM (Proton Exchange Membrane) technology.

The transportation and distribution of hydrogen require storage in the form of compressed or liquid gas. Compression losses are in the range of 10 to 20% in energy for pressures between 300 and 700 bar. For hydrogen liquefaction, losses are around 30% for large...