While it is capable of providing constant power, hydrogen fuel cells are also being considered for providing backup power to data centers. This is greatly appealing to data center operators as a more environment-friendly replacement for traditional diesel generators. This change would see the use of fast-start fuel cells, such as proton exchange membrane (PEM) fuel cells which could take the place of diesel generators.

The key benefit and primary motivation for installing hydrogen fuel cells within a data center is to reduce carbon emissions. As stated, some fuel cells, such as SOFCs, can use natural gas. While it is less damaging to the environment than diesel, it still results in significant carbon emissions.

SOFCs and PEM fuel cells differ from one another in their construction, materials, and operation. In a high-level view, the primary differences are the electrolyte materials (where the hydrogen and oxygen react) and operating temperatures. SOFCs operate at high temperatures, requiring longer start-up times and as a result, only being suitable for continuous power supply. PEMs, by contrast, operate at lower temperatures and are capable of fast-start or continuous operation, but are a more expensive option.

From a mechanical perspective, designing a hydrogen storage system is significantly more complex than a diesel storage system. Hydrogen has more storage options available however, it presents higher risks than diesel such as greater flammability and explosivity, higher pressures, potential for low temperature, or chemical storage methods which are all hazardous. This therefore requires the mechanical design for such a system to comply with rigorous safety standards.