The hydrogen car with a fuel cell: electricity on board

Useful to know

The hydrogen fuel cell vehicle is referred to as the FCEV. Its wheels are powered by an electric motor, but much of the electricity required is produced on board. For this purpose, hydrogen stored in a tank and a fuel cell are used. It's a different technology than an engine that burns hydrogen. The generic name "hydrogen car" can hide the difference, so in technical description it is important to explicitly state the type of conversion. [1]

The fuel cell converts chemical energy into electrical through an electrochemical process. Hydrogen and oxygen are involved in a reaction in which electricity, water and heat are obtained. Unlike the battery, which stores a certain amount of energy in itself, the cell can continue working until the necessary reagents are passed. The U.S. Department of Energy is looking at fuel cells for other applications as well, so the car is one use of more general technology. [2]

There is usually a battery in the vehicle as well. It can absorb energy from regenerative braking and assist in propulsion when additional power is needed. The fuel cell, battery, and electric motor are not interchangeable components: they produce, store, and convert energy differently. The control electronics coordinate these flows. Therefore, the lack of a large battery as the only primary stock does not mean the absence of an electrical storage system. [1]

Among the other important parts are the hydrogen tank, air supply, cooling and power electronics. Temperature control is necessary because the process releases heat. The components should work as a system, not just as an independent current source and electric motor. Their exact location and characteristics depend on the model. The AFDC scheme is useful as an explanation of functions, but should not be taken as a service card of any vehicle produced. [1]

Charging with hydrogen requires a corresponding infrastructure. This is different from connecting to an electric charging station. AFDC places the availability of hydrogen stations among the practical conditions for the use of FCEVs. Therefore, interesting technology alone does not prove convenience for a specific route. When evaluating for a region, it is necessary to check the actual stations and compatibility, instead of a map or example from another country being taken as a description of the local situation. [3]

The claim of water separation in the operation of the cell describes the process on board. It is not a complete assessment of all the impacts of hydrogen production and delivery. This distinction is particularly useful when comparing technologies: one question is how the wheels move, the other is where the energy carrier comes from. When the two issues are dealt with separately, the FCEV becomes more understandable as an electric fuel cell system, rather than as an indefinite promise of a car without any restrictions. [2, 3]