La geothermal energy, extracted from the Earth's subsoil, is one of the most efficient, sustainable and increasingly used renewable energy sources worldwide. This type of energy uses the internal heat of the earth to generate heating, cooling and, in some cases, electricity. One of its main advantages is that it is available practically anywhere, regardless of external weather conditions. Geothermal energy is especially useful for air conditioning buildings by using geothermal heat pumps, which provide heating in winter and cooling in summer.
Operation of a geothermal installation
The operating principle of a geothermal installation is quite simple. The temperature in the earth's subsoil remains constant throughout the year, typically around 18 degrees at a depth of 100-150 metres. During the winter, heat is extracted from the subsoil and transferred to the building by means of a geothermal heat pumpIn summer, the process is reversed: warm air from the building is transferred underground, helping to cool the interior of the building.
This system is highly efficient, as it takes advantage of the thermal stability of the subsoil to reduce energy consumption. Compared to conventional air conditioning systems, geothermal installations can save up to 70% on heating costs and 50% on cooling costs.
The example of Madrid: A highly energy-efficient building
A clear example of the application of this type of energy is in a building located in the Chamartín district, Madrid. This building, built in the former Municipal Urban Planning Department, stands out for its geothermal power of 540 kWThanks to this installation, it has managed to surpass another building in the city that used geothermal energy with a power of 430 kW.
To achieve this efficiency, 70 perforations underground, reaching depths of up to 130 metres. At these depths, the temperature remains stable, ensuring the efficient operation of the system throughout the year. Architect Alberto Rubini highlights that the water circulates through a closed circuit, maintaining constant thermal exchanges.
Geothermal installation: Technical details
The geothermal heat pumps They are the key component of such an installation. These pumps are responsible for transferring heat from the ground to the building and vice versa. The process is based on the use of a fluid that circulates through a system of pipes buried deep underground, known as a closed circuit. This circuit is designed to ensure that the fluid reaches the right temperature (around 18 degrees), taking advantage of the thermal stability of the subsoil.
In the case of the Chamartín building, the heat pump is located in the lower part of the building and is used both to provide heating in winter and to cool in summer. In this way, the building becomes one of the most sustainable thanks to its zero impact on CO2 emissions, which is up to 19 times less than that of a conventional property.
Advantages of geothermal installations
- Reduction of CO2 emissions: This type of energy is completely renewable and does not emit greenhouse gases during its operation.
- Economic savings: The energy consumption of a geothermal installation is significantly lower than that of a traditional installation. In the case of the Chamartín building, energy consumption is only 15 kWh/m2 compared to 248 kWh/m2 for conventional buildings.
- Long useful life: The components of a geothermal installation, especially the collection systems, have a useful life of up to 50 years or more.
- Global sustainability: The building is designed with other measures that contribute to its sustainability, such as ventilated facades and materials with high insulating capacity.
More examples of geothermal installations in Madrid
In addition to the Chamartín building, Madrid has numerous other emblematic examples that have opted for geothermal energy to achieve greater energy efficiency. These include the BBVA headquarters in Las Tablas, which has a geothermal installation capable of generating 122 kW of thermal power. This installation has been key to the building obtaining LEED certification, an international standard for sustainable buildings.
Another notable case is that of Moncloa College, where a geothermal air conditioning system has been installed which, in addition to providing heating and air conditioning, has drastically reduced CO2 emissions. Thanks to this system, energy efficiency has been achieved that is much higher than that of other university buildings.
Impact of geothermal energy on emissions reduction
The use of geothermal energy not only represents economic savings, but also contributes significantly to the reduction of CO2 emissionsIn the case of Madrid, geothermal energy has achieved a considerable reduction in emissions from the residential sector. According to data from the Government's Climate Change Office, the residential sector in Spain is responsible for 9% of greenhouse gas emissions.
Spain has committed to reducing emissions by 30% by 2030 compared to 2005 levels, in line with the Paris Agreement. The use of geothermal energy in residential buildings is one of the most effective ways to achieve this goal.
In short, geothermal energy is presented as an efficient, sustainable and economically viable solution for the air conditioning of buildings. Whether in small homes or large buildings, as described in Madrid, this technology has enormous potential to contribute to the decarbonisation of the residential sector and improve the quality of life of building occupants.