Fuel cells use an electrochemical process to convert the chemical energy in a fuel to electricity. For stationary power, fuel cells are used for distributed generation (electricity only) and are also configured for combined heat and power (CHP). There are 126 fuel cells installed in the United States that are configured for CHP operation, accounting for a combined capacity of 67 MW. The majority of these fuel cells are used in commercial and institutional buildings—such as universities, hospitals, nursing homes, hotels, and office buildings—where there is a relatively high coincident demand for electricity and thermal energy.