A plant geotermoelettrico has the function to transform into electricity heat energy present in geothermal fluid (water vapor or a mixture of water and water vapor) that form thanks to the contact of water with layers of hot rock.

The peculiarity of the basins geotermoelettrici exploited by such equipment is due to the fact that the geothermal fluid is available.

Generally a plant geotermoelettrico consists of the following components:

1. System for the collection, treatment and conveyance of the geothermal fluid up to the system of producing electricity, wells, security systems and overflow to mouth well, pipes for conveying separation systems, water-steam);
2. Production system of electricity(intake duct in the turbine, turbine-generator, transformer-elevator and connection to the transport network);
3. System for the treatment of spent steam(condenser and pump condensate extraction, cooling tower for air, gas extraction system condensed);
4. System of reinjection of waterin the basin geotermoelettrico.

May also be present systems for the reduction of certain compounds present in noncondensable gas (hydrogen sulfide and mercury), in order to limit the environmental impacts of the plant. Emissions into the atmosphere of these types of plants depend on the characteristics of the geothermal fluid but, per unit of energy produced, are decidedly lower than those resulting from plants fed with fossil fuel.