Geothermal power production represents predictable output and long-lasting resources.
Having no reliance upon transitory environmental states such as wind and sunlight, geothermal facilities can produce electricity 24 hours a day, 7 days a week. As a result, geothermal power plants have a high capacity factor, demonstrating a level of consistency not found in other sources. The EIA report lists geothermal power as having the highest capacity factor (92%) of all the energy sources discussed, higher even than coal (85%), gas (87%), or biomass (83%). For comparison’s sake, the capacity factors for wind, solar and solar PV are listed as 34%, 20%, and 25% respectively.27
Geothermal power’s reliability is also demonstrated by the longevity of the resource and its history of successful exploitation. The first electricity from geothermal steam was produced in 1904 by Prince Piero Ginori Conti in Larderello, Italy, and it went into operation as the first commercial geothermal power plant in 1913. This field is still producing today. In fact, with the exception of a few years during World War II, this field has been producing continuously for more than a century. Similarly, The Geysers field in California has been exploited consistently since the 1960s, and thanks in part to the wastewater injection practices which were enacted to sustain the resource, this field accounts for approximately one-fifth of the clean energy produced in California today