Environmental awareness paired with rising energy costs has driven the emergence of new solutions in recent years. This is evident with geothermal homes, structures that can operate independently from electricity and gas networks. Geothermal energy is a renewable, clean source drawn from the earth’s crust. It maintains comfortable, steady indoor temperatures between 19 and 21 degrees year-round. Installing geothermal systems can reduce reliance on fossil fuels, leading to lower emissions and cost savings for residents. The system can be complemented with solar panels to reach true energy independence.
Like solar energy, geothermal installations come with upfront costs. Energonova Renovables, a company specializing in such setups, notes that installing geothermal energy in a 200-square-meter single-family home in Madrid costs around 25,000 euros, roughly 125 euros per square meter. If underfloor heating and cooling are included, an additional 40 to 50 euros per square meter is added. The final price depends on the home’s size since larger houses require more power and deeper geothermal drilling.
According to the Rastreator comparator, using data from Red Eléctrica Española, a four-member household spends no less than 135 euros monthly on utilities, equating to over 1,620 euros per year. With this conservative figure, a family that adopts geothermal power in their home may recoup the investment in about 15 years. As electricity and gas prices rise, geothermal energy amortization times shorten. Beyond the financial aspect, the technology produces no harmful emissions during operation.
Geosolar and Without Plug
Grupo Index stands out as a company focusing on promoting and building geothermal homes. Since its inception, it has delivered more than 1,750 homes across 50 single-family developments in the Community of Madrid. The firm currently has nine projects in progress in Boadilla del Monte, Las Rozas, Arroyomolinos, Villaviciosa de Odón, and Colmenar Viejo. The developer emphasizes geosolar and freestanding homes and states, “We create energy producers, not consumer homes.” Teresa Serrano, a spokesperson for the company, notes that the firm operates two house models: geosolar, which connects to the grid when energy is abundant, and completely off-grid homes that are self-sufficient.
Grupo Index now has a project featuring 26 freestanding houses in Cubas de la Sagra, Madrid. The landing page for a new study promises real out-of-pocket savings because it can end electricity bills and energy bills forever. For geo-solar power plants, the monthly cost for a single-family home is reported to be between 25 and 35 euros, based on invoices provided to EL PERIÓDICO DE ESPAÑA.
Differences Between Geothermal and Aerothermal
Another system gaining traction in Spain is aerothermal energy. Geothermal uses the earth to stabilize temperatures, while aerothermal relies on ambient air. Industry sources cited by this publication indicate that air-temperature systems can be cheaper to install, though their performance generally trails geothermal, particularly in colder regions. Market data from Energanova shows a balance between adopting geothermal and aerothermal, with 800 geothermal and 400 aerothermal installations to date. “The shift happened because people were persuaded; now they are convinced,” the company reports.
Both aerothermal and geothermal systems deliver efficiency and environmental benefits. While aerothermal heat pumps are advancing, they draw on a less stable energy source like air, which can reduce performance at low outdoor temperatures. In contrast, geothermal systems draw heat from a thermally stable subterranean source, typically delivering higher energy efficiency. The gap in performance between the two technologies tends to widen as winter temperatures drop, according to Enertres, a renewable energy specialist, in a recent assessment.