Fuel cell engines are primarily used in civilian applications like rail systems, personal transport, and IndustrialMechs. These engines generate electrical power by combining two suitable reactants (a fuel and an oxidizer) in a controlled pair of redox reactions, providing power to to operate the vehicle's propulsion and other electrical systems. A fuel cell engine has several advantages over the typical internal combustion engine. A fuel cell system is usually about 40% lighter than a comparable internal combustion engine. While they require an oxidizer to operate, they are readily able to accept a stored oxidizer along with their fuel, making it a good choice for submarines, satellites, and naval applications. As most fuel cells run on hydrogen and oxygen, they have no exhaust other than water vapor; therefore, they are also used as generators for buildings and other large structures. Their main drawback, when compared to the ICE counterparts, is their range: a fully fueled fuel cell vehicle only has two-thirds the range of a vehicle equipped with a comparable ICE.
Compared to a fusion or fission reactor, the fuel cell's biggest advantages are cost and temperature. They run cooler than an ICE and much cooler than a comparable fusion power plant. In addition, the fuel cell system is much cheaper than a fusion reactor. These advantages are offset by the fuel cell's greater weight, need for fuel, and comparatively low range. Recently several manufacturers have begun creating advanced fuel cell engines rated for combat use. Typically these are seen on combat vehicles, but manufacturers claim that they can be adapted for use on BattleMechs. One drawback to these combat fuel cell engines is that they require the same type of power amplifiers used on vehicles powered by an ICE system.
Fuel cell engines receive a single heat sink for free. They can carry heat sinks, as listed in the TechManual.
- Tactical Operations, pp. 133-134, "Power Generators"
- TechManual, p. 68, "Fuel"
- Tactical Operations, p. 306-308, "Engine Systems"
- TechManual, p. 62, "Engines"