Geothermal energy:

• It is a renewable heat energy of the earth to generate electicity and it is a non-conventional energy.
• The geothermal resources tapped to generate electricity are far more intense than those used for space heating and can reside as deep as 10,000 feet below the earth's surface.
• Capital costs for the construction of geothermal power plants are much higher than for large coal-fired plants or new natural gas turbine technologies.
• But geothermal plants have reasonable operation and maintenance costs and no fuel costs. Though more expensive than wind power in most cases, new geothermal electricity generation facilities are increasingly competitive with fossil options.
• Geothermal plants can operate around-the-clock, which increases their value from a reliability point-of-view, unlike some intermittent renewable fuels such as solar and wind.

Electricity from geothermal energy:

• Geothermal electricity generation technologies consist of either flash or binary technology.
• With flash technology, water from 300 to 700 degrees Fahrenheit, but still in liquid form, is piped from its highly pressurized underground reservoir into a geothermal facility.
• Once this super-heated water is released, it flashes into steam that then drives a conventional turbine generator.
• With binary technology, underground reservoir waters of lower temperatures are used for flashing. Heat from geothermal water is transferred to a second binary liquid, which flashes into vapor upon heating, and that vapor is used to drive turbines.
• With dry steam technologies; a much rarer fuel source highly pressurized geothermal vapor is used directly to drive a turbine.