Geothermal energy is the exploitation of terrestrial heat by humans. The exploitation of geothermal energy consists of extracting heat from the ground and using it to heat homes.
Understanding geothermal energy
What is geothermal energy?
Geothermal energy, when it involves heating an individual house, is called geothermal energy at very low energy. It is to exploit only the superficial heat of the ground which, in general is around 15° C. It is also possible to extract this heat from groundwater.
The upper layers and groundwater benefit from the heat radiated by the sun and the heat flux flowing to the surface. The heat of the thermal water is extracted by means of a heat exchanger (heat pump) which stocked at once a heating network.
Surface geothermal energy is used to heat houses and their running water.
The use of geothermal energy
Geothermal energy is used, among other things, to provide individual homes with energy.
Geothermal energy is an almost inexhaustible and clean energy. On the other hand, its use is restricted because it is difficult to access. However, it is more common to find geothermal energy producers in areas of volcanic activity.
This sustainable source should, in the future, be democratized and quickly become a popular means of heating.
To measure the amount of geothermal heatthe thermal megawatt hour unit is MWth. A MWth equals 3.6x103 megajoules. Do not confuse the electric watt and the thermal watt.
How does geothermal energy heat a home?
There are different heat exchangers.
- Heat pumps geothermal which allows the extraction of heat and its injection in a circuit that will increase or lower the temperature according to the needs of the home. They are often equipped with geothermal probes in which circulates a heat-absorbing heat-transfer liquid or energy piles containing cold water which warms up in contact with the heat of the ground.
- Compression heat pumps that use heat through the evaporation of a refrigerant that goes through a circuit. They should not be confused with adsorption heat pumps that use geothermal motive power.