| SOLAR GEOTHERMY |
www.geotics.net |
The Earth’s crust absorbs a large part of the energy from the Sun as heat. Due to the Earth’s large size, the temperature in the subsoil is more or less constant from 2 meters depth onwards, though it changes slightly depending on the soil’s characteristics and on the solar radiation typical of each region. In Spain the temperature reaches 15ºC.
With a good caption system and a geothermal air heat pump we can transfer the heat of this source of energy (subsoil, at 15ºC) to another source (accumulator of Sanitary Hot Water –SHW- or water circuit, 50ºC) to be used in a domestic heating system and/or in a home SHW.
Using the same air heat pump we can also absorb the outside heat at 40ºC and transfer it to the subsoil so that, applying the same system, we can supply both hot and cold air. In sum, with one installation we can solve the air conditioning of the entire house.
The energy efficiency of an air conditioning system, using the subsoil as a heat source at 15ºC, is of at least 450% when heating and 600% when cooling. This is possible because the system does not generate all the heat but instead transfers it from one source to another.
For example, a house in the Vallès area would spend about 700 €/year to maintain temperatures and to have hot water using a geothermal system. If instead it used natural gas (for heating) and electricity (for cooling), it would cost about 1500 €/year.
Geothermal conditioning systems are highly ecological since there is no combustion or generation of CO2.
The system’s efficiency represents an energy saving of 75% during heating and 83% during cooling. This represents an efficiency improvement of about 50% with compared to traditional air heat pump systems.
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