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Geothermal Technology
Ground Source Heat Pumps
Commonly referred to as Geothermal, Ground Source Heat Pump (GSHP) technology can be used to heat your house and swimming pool in the winter and cool the house in the summer. Geothermal heating systems extract energy from the ground around us. GSHP work in the following way.
The top 15 meters of the Earths surface remains at the relatively constant temperature of around 12oC. This natural store of heat can be extracted and used to heat buildings and hot water systems. This store of energy is constantly renewed by the Sun, Rain and the Earth’s molten core and is therefore a completely renewable, free source of energy, an abundant resource in Spanish regions such as Alicante, Valencia and Murcia.
 Pipes (captors) are buried in the ground, either as boreholes or in horizontal trenches. The pipe is a closed circuit, which is filled with a mixture of water and antifreeze. The liquid is pumped round the pipe, absorbing the heat from the ground. In winter the ground is warmer than the air and buildings above it. The anti-freeze mixture absorbs heat from the ground, which is then concentrated and transferred to the buildings. The heat obtained is used to provide temperature heating systems such as under floor heating and hot water systems.
The efficiency of a ground source heat pump is measured as a Coefficient of Performance (CoP). This is the ratio of units of heat output for each unit of electricity used to drive the compressor and pump. A CoP of 4 means that for every kilowatt of electricity used, you get 4 kilowatts of useable energy in the form of hot water. The flow temperature of this hot water is typically between 35oC and 45oC, which is lower than that achieved by a domestic oil-gas boiler.
The National Energy Foundation (UK) describes the Geothermal Energy Technology as follows,
“When the sun shines on the ground its’ heat energy is absorbed. During the summer, solar heat is stored in the surface layer of the soil. Strictly speaking, the energy source that is used for ground source heat pumps is the sun and not the heat from the earth (geothermal energy). Down in the bedrock there is also a source of heat that stays at practically the same temperature all year round. Ground source heat pumps extract this energy and use it for space heating.
Geothermal Heat Pumps need some power to operate. However for 1 unit of energy they use they generate 4 units of power. The energy generated by a ground source heat pump can be considered 100% renewable if the power to operate the pump comes from solar electric panels or a wind turbine for example”.
Aerothermal Technology
Air Source Heat Pump Technology (ASHP)
Where the use of ground source heat pumps has been considered, but it is not possible to drill a ground probe or install a surface ground loop on the property, an Air Source Heat Pump (ASHP) may well be the answer. The only space requirement is an outside wall making them ideal for homes with limited land space. With no need for ground-works, installation costs are kept to a minimum.
Air source heat pumps work by converting the energy in the outside air into heat, creating a comfortable temperature inside the house as well as supplying energy for the hot water system. As with all heat pumps, air source systems are most efficient when supplying lower temperature systems such as under floor heating.
The efficiency of an ASHP is also measured as a Coefficient of Performance (CoP). A CoP of 4 means that for every kilowatt of electricity input, you get 4 kilowatts of energy in the form of hot water. The flow temperature of the hot water is typically between 35oC and 45oC, which is lower than that achieved by a domestic oil-gas boiler.
An ASHP will cover the heating requirements of a well-insulated property in all but the most extreme conditions. When used in combination with an immersion heater both heating and hot water needs are met, the immersion heater boosting water temperatures when necessary. An outside air source heat pump working efficiently can reduce energy consumption for heating by up to 75% when compared to conventional oil-gas heating systems.
The Benefits of Heat Pump Technology
The benefits to you from embracing Geothermal Heat Pump or Aerothermal Heat Pump technology to heat your home are that they are,
- Economic and are typically 75% cheaper to run than comparable oil-gas systems,
- Environmentally friendly, as they produce zero gas emissions of Carbon Dioxide (CO2), Sulphur Dioxide (SO2) and other green-house gases,
- Do not use combustion and do not therefore emit the dangerous Carbon Monoxide gas, which has caused so many accidents and fatalities,
- They use a completely natural and renewable energy source,
Heating systems based on Ground Source Heat Pump or Air Source Heat Pump technologies also have the advantage that they can be reversed in the summer and used to cool the same buildings. They effectively transfer the heat from the building back into the environment.
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