What is Geothermal Power?
Geothermal Power or Electricity Generation is the commercialization and development of the Earth’s natural heat, steam, or brine to be leverages as a reliable, baseload form of electricity generation.
Depending on the characteristics of the geothermal resource, e.g. based on resource temperatures, electricity generation takes either place in conventional steam turbines or binary plants. The earliest plant known to have generated electricity from geothermal, is an early installation at Lardarello in Tuscany, Italy in 1904.
“Conventional steam turbines require fluids at temperatures of at least 150 degrees Celsius, and are available with either atmospheric (back-pressure) or condensing exhausts. Atmospheric exhaust turbines are simpler and cheaper. The steam, direct from dry-steam wells or, after separation (of water from steam), from wet wells, is passed through a turbine and exhausted to the atmosphere. With this type of unit, steam consumption per kilowatt-hour (kWh) produced is almost double that of a condensing unit.
The condensing units, having more auxiliary equipment are more complex than the atmospheric exhaust units, and the bigger sizes can take twice as long to construct and install. Condensing plants with a capacity of 55 to 60 MWe are very common, but plants of 110 MWe have also been constructed and installed.” (source: Dickson/ Fanelli, 2006)