The need for backup diesel generators in a data center is obviated by using fuel cells to convert a fuel to electrical energy, which provide backup power to equipment in a data center, which may include the servers in the data center and other important systems that normally use utility power. When the utility power fails, the equipment switches to backup power that is provided by fuel cells supplied with fuel (such as natural gas), possibly using a source of temporary power (e.g., a UPS or direct tie-in of batteries) while the fuel cells come online. The fuel may also be used to power a turbine or generator, coupled to a chiller for providing a cooled liquid to a cooling system.