What Is Geothermal Energy?

As you descend deeper into the subsoil and the Earth’s crust, underground rock and water become hotter. This heatIn the field of statistical thermodynamics today, heat refers to the transfer of the thermal agitation of the particles making up matter... is referred to as geothermalDescribes the technology used to tap subsurface heat to produce energy... energy, and can be recovered at various depths and temperatures using a range of techniques. It represents a renewable energyEnergy sources that are naturally replenished so quickly that they can be considered inexhaustible on a human time scale... source that can heat – or cool – houses, apartment blocks, factories and farm buildings. If used to drive a turbine, the heat can also be converted into electricityForm of energy resulting from the movement of charged particles (electrons) through a conductor... .

The principle behind deep low-temperature geothermalDescribes the technology used to tap subsurface heat to produce energy... energy is the same as for other low-temperature varieties, except that the wells descend further below the surface, to depths of 200 to 2,500 meters, and that the water temperatures are higher, generally between 30°C and 90°C. The water is captured via one well then reinjected underground through another, forming a “doublet”. This technique can be used to heatIn the field of statistical thermodynamics today, heat refers to the transfer of the thermal agitation of the particles making up matter... entire neighborhoods with thousands of inhabitants or industrial parks.

Very low-temperature geothermalDescribes the technology used to tap subsurface heat to produce energy... energy can be recovered from heatIn the field of statistical thermodynamics today, heat refers to the transfer of the thermal agitation of the particles making up matter... sources under 30°C located at depths of up to 200 meters below the surface. As the temperatures are not high enough for direct use through a heat exchange system, additional processing via heat pumps is needed to increase them to a level sufficient for heating. This type of energy is used in single-family homes, apartment blocks and commercial buildings.

High-temperature geothermalDescribes the technology used to tap subsurface heat to produce energy... energy can be used to generate electricityForm of energy resulting from the movement of charged particles (electrons) through a conductor... or a combination of heatIn the field of statistical thermodynamics today, heat refers to the transfer of the thermal agitation of the particles making up matter... and powerIn physics, power is the amount of energy supplied by a system per unit time. In simpler terms, power can be viewed as energy output... . This requires capturing hot water or steam at temperatures of at least 150°C located between 1,500 to 5,000 meters below ground. Projects are often developed in areas characterized by volcanic activity.

Why not “create” hot water beneath the surface by injecting cold water into dry, hot rock formations and then recovering the water once it has been heated through contact with them? The use of end-of-life, or depleted, oil fields is also being studied.