Fuel Cell Electric Vehicles (FCEV) are electrically propelled vehicles that use electrochemical devices (fuel cells) to generate electricity through a chemical reaction between hydrogen stored in the vehicle and oxygen in the air, without combustion processes.
This reaction produces the electricity needed to power the vehicle engine and, as by-products, only water and heat, with no harmful emissions.
The main feature of FCEVs is that the electricity needed to power the engine does not come from rechargeable batteries but is produced directly in the vehicle via fuel cells.
However, it must be considered that hydrogen production requires energy and can come from fossil or renewable sources, so the overall environmental impact depends on the origin of hydrogen production.