Relating to, or caused by, the internal heat of the Earth: Mr. Thompson's house was warmed up by geothermal energy.

While at the hot springs, Jill let her feet dangle in the water and enjoyed the geothermal warmth it provided.

A system used to extract heat from the less productive margins of existing geothermal fields, or from entirely new fields that are lacking sufficient production capacity under current conditions: Enhanced geothermal systems utilize a combination of hydraulic, thermal, and chemical processes, such as rock fracturing, water injection, or water circulation.

The use of geothermic heat in farming: Geothermal agriculture is the use of low-temperature geothermal water to warm irrigation water or to sterilize soil.

The use of geothermal heat in fish farming: Geothermal aquaculture is used to warm up the water in order to provide a controlled environment for the husbandry of marine organisms.

The use of naturally-cooler water, or air, to lower the temperature of a building, as opposed to air or water that is artificially cooled: Those who utilize heat pumps in a system of geothermal cooling save up to 70% on heating expenses in addition to 50% on cooling costs.

The process of drilling a well to explore for or to extract geothermal energy, or to re-inject thermal waste water in the ground after power generation: Geothermal drilling entails boring a hole deep into the ground and pumping water back up. The method of geothermal drilling is a fantastic way of heating one's home.

You may see more information about geothermal drilling here.

1. Energy in the form of natural heat flowing outward from within the plant Earth and contained in rocks, water, brines, or steam: Geothermal heat is produced mainly by the decay of naturally occurring radioactive isotopes of thorium, potassium, and uranium in the Earth's core.

Geothermal energy is produced by tapping the Earth's internal heat. At present, the only available technologies to do this are those that extract heat from hydrothermal convection systems, where water or steam transfer the heat from the deeper part of the Earth to the areas where the energy can be tapped.

The amount of pollutants found in geothermal vary from area to area but may contain arsenic, boron, selenium, lead, cadmium, and fluorides. They also may contain hydrogen sulphide, mercury, ammonia, radon, carbon dioxide, and methane.

Getting the Earth's Heat

Geothermal power plants, which tap hot subterranean water or steam, are high on the lists of at least thirty states in the U.S. which are requiring utility companies to generate some portion of their electricity from such renewable sources.

Most utilities have not pursued geothermal energy primarily because up-front costs, including exploratory drilling, can be expensive since geothermal taps deep reservoirs, not groundwater, which collects much closer to the surface.

An extensive study recently released by the Massachusetts Institute of Technology has shown that the heat available under ground is surprisingly plentiful nationwide.

More information about special Geothermal Energy sources.

The rate of temperature change in soil and rock from the surface to the interior of the Earth: The geothermal gradient on the average is estimated to be an increase of about +10°C per kilometer.

Heat pumps which consist of underground coils that transfer heat from the ground to the inside of a building: The large company had a ground source heat pump to heat and to cool their many buildings.

1. The extraction of valuable minerals from geothermal fluids: By the way of geothermal mining solid homogeneous inorganic matter, like market-grade silica, can be obtained from a geothermal brine.
2. The process of purposely transporting geothermal energy from beneath the Earth's surface: Geothermal mining can be useful for human utilization, for example for the building of a well and pipeline system to bring heated water to a power plant.

An industrial heat-producing manufacturer in which the prime mover is a steam turbine: Geothermal plants are driven either by vapor produced from hot water or by natural condensation that derives its energy from the hotness found in rock formations of the planet.

Like other related "plant" references, this entry is apparently linked to the action of pressing on a shovel, or some other apparatus, with the "sole of the foot" in order to work the soil for the development of plants.

A subsurface system consisting of a large volume of hot water and steam trapped in a porous and fractured hot rock underneath a layer of impermeable rock: Some geothermal reservoirs can be commercially developed as an energy source.

A localized geological environment in which circulating steam, or hot water, carries some of the Earth's natural internal heat flow close enough to the surface to be utilized for productive human use: A geothermal system is one kind of technological system that makes use of this heat as an energy source, such as to power an electrical power plant, or to heat or to cool a building.