Geothermal Energy
___________________________________________________________________________________________________________________________________________The geothermal energy is the energy that is obtained by harnessing the internal heat of the Earth, which globally can be considered continuous and inexhaustible on a human scale. A geothermal site is an area of the subsoil where the geothermal resource is likely to be exploited by man.
Geothermal deposits are classified according to the energy level of the resource they contain.
They can be classified as follows:
High temperature: They exist in the most active areas of the earth's crust at temperatures above 150ºC. They are deposits from which enough heat can be extracted to produce electrical energy from water vapor. They are located mainly in areas with high geothermal gradients (relationship between temperature variation and depth) and are located at very variable depths.
On average temperature: Generally they reach temperatures between 100 and 150ºC, which allows its use for electricity production, but with a lower yield than high temperature. The use can also be direct in the form of heat for urban heating systems or industrial uses. They are located in areas with a favorable geological and structural context and a higher than average gradient.
Low temperature: They reach temperatures between 30 and 100ºC. Its use focuses on thermal uses in urban heating systems, industrial processes and spas. They are usually located in areas with a favorable geological context with presence of deep aquifers, although the gradient may be close to the average gradient.
Very low temperature: They are the deposits whose temperature is below 30ºC. They are usually used as a heat exchanger in air conditioning systems by heat pump. These deposits can be located at any point, since the geothermal gradient only conditions the efficiency of the system.
On average temperature: Generally they reach temperatures between 100 and 150ºC, which allows its use for electricity production, but with a lower yield than high temperature. The use can also be direct in the form of heat for urban heating systems or industrial uses. They are located in areas with a favorable geological and structural context and a higher than average gradient.
Low temperature: They reach temperatures between 30 and 100ºC. Its use focuses on thermal uses in urban heating systems, industrial processes and spas. They are usually located in areas with a favorable geological context with presence of deep aquifers, although the gradient may be close to the average gradient.
Very low temperature: They are the deposits whose temperature is below 30ºC. They are usually used as a heat exchanger in air conditioning systems by heat pump. These deposits can be located at any point, since the geothermal gradient only conditions the efficiency of the system.
Currently, in Catalonia, the most widespread use of geothermal energy is geothermal use of very low temperature by means of a heat pump for the air conditioning of buildings. It is an efficient technology with outstanding energy savings and with the advantage that the geological conditions for its use are not very demanding and you can take advantage of the use of almost the entire territory.
There are different systems of use of geothermal energy of very low temperature, which are classified into two main types:
Open systems: Where water is collected from an aquifer for its use.
Closed systems: Where the heat pump fluid circulates through a closed changer circuit located in the subsoil.
Depending on how the changers are located in the subsoil we can distinguish between uses with vertical changers or horizontal changers
There are different systems of use of geothermal energy of very low temperature, which are classified into two main types:
Open systems: Where water is collected from an aquifer for its use.
Closed systems: Where the heat pump fluid circulates through a closed changer circuit located in the subsoil.
Depending on how the changers are located in the subsoil we can distinguish between uses with vertical changers or horizontal changers
