Geothermal Energy has a steady, high capacity, the best of all renewable energies
Capacity factors are an important measure of electric generator usage. They describe how intensively a fleet of generators is run. A capacity factor near 100% means a fleet is operating nearly all of the time. It is the ratio of a fleet's actual generation to its maximum potential generation.
In December 2013, the U.S. Energy Information Administration (EIA) began publishing tables of monthly capacity factors for 16 different fossil and non-fossil fuel and technology combinations in the Electric Power Monthly.
EIA's new tables include capacity factors for individual renewable generating technologies (see chart below). Geothermal and waste technologies operate fairly steadily and at high capacity factors. Intermittent renewable sources like solar and wind tend to have lower capacity factors, as their output varies with the availability of the sun and wind on both a daily and seasonal basis. Solar generators—particularly solar thermal—operate at a minimum during winter months, while the U.S. wind fleet on average has a period of low production during the late summer. Hydroelectric generators show both seasonal and annual variations reflecting changing levels of precipitation, river flow, and snowmelt.
