Geothermal Energy is clean heat that comes from the sun. The heat from the sun comes from the radioactive decay of minerals. Geothermal heat is produced by drilling wells into the crust of the Earth and those holes are dug 3 to 10 kilometers deep. There are many ways to pull out the heat from the Earth, but the most used and common are water and steam. Homes and buildings are heated by the hot water that has been extracted from the earth. The heat can be produced by letting the hot water flow through the buildings or the hot water will be pushed through heat exchange that will allow heat to flow through and heat homes and buildings. Geothermal heat also can be a valuable source of electricity and power. When geothermal heat creates steam, the steam spins through the turbines on a generator.
3 Types of Geothermal Power Plants
- Dry Steam Plants – Dry steam plants use steam which is called hydrothermal fluids. The steam that is produced will create electricity by flowing directly through a turbine and resulting in the generator starting. Out of all geothermal power plants, dry steam plants were the first to be built and used in Italy in 1904. Much time has passed and power plants are still used and are very effective today.
- Flash Steam Plants – Flash steam plants are the most reliable and common method of producing power. Fluids are pushed through at high temperatures of 360 degrees at a very low pressure. This results in some of the fluid to vaporize. The vapor then flows through the turbine which also results in the generator starting up.
- Binary Cycle Power Plants – In a binary cycle power plant, unlike dry steam plants and flash steam plants, water or steam does not come in contact with any generator or turbine. Two fluids at different temperatures flow through a heat exchange. Heat that comes from these fluids, both primary and secondary, then results in vapor. Which then drives the generators and turbines.