Large-scale infrastructure like airports requires a constant supply of energy to keep operations running. Facing that challenge, geothermal energy is emerging as a key solution, turning the ground beneath our feet into an efficient source of heating and cooling that doesn’t depend on outside weather conditions.
An airport is far more than a runway and a terminal. Offices, retail areas, technical facilities, hangars, and other buildings all need to maintain proper temperatures year-round. On top of that come the constant energy demands of an operation that serves thousands of passengers and workers every day.
That’s why, beyond adding renewable sources to generate electricity, airports are also looking for ways to meet their thermal energy needs—the energy used for heating, cooling, and hot water. Geothermal energy is one such option: a technology that taps into heat stored underground and can be integrated into the climate control systems of large buildings.
These systems draw on the thermal energy stored inside the Earth. In building applications, they allow heat to be exchanged with the ground, providing heating during the cold months and cooling during the warm ones.
One of the most widely used approaches is the geothermal heat pump, which uses the ground either as a heat source or as a place to send heat. This can be done through closed-loop systems with buried pipes, or through solutions that draw on groundwater.
One key advantage is that ground temperature stays far more stable than outside air temperature, making it a reliable thermal source year-round.
These applications typically fall under what’s known as low-temperature geothermal energy, as opposed to higher-temperature geothermal resources used for electricity generation. For buildings, the main interest lies in harnessing that stored energy for heating and cooling.
A partner in decarbonization
Airport terminals cover vast areas that need climate control for much of the year, and their facilities require stable temperatures to keep passengers and staff comfortable.
That combination makes geothermal energy a compelling option as a thermal energy source. Rather than relying solely on conventional heating and cooling systems, an airport can tap into the ground as an additional, sustainable energy source for its facilities.
This technology doesn’t operate in isolation, but it can be paired with other efficiency and emissions-reduction measures already in use, such as Sustainable Aviation Fuel (SAF), to help drive decarbonization across aviation and air transport. Generating renewable electricity through photovoltaic panels, improving building efficiency, and electrifying various types of equipment are all part of a broader set of solutions helping decarbonize airport infrastructure and move the industry toward more sustainable models.
Sweden: An aquifer for groundwater energy
One of the most notable examples is Stockholm Arlanda Airport in Sweden. Since 2009, the airport has used an underground aquifer as an energy storage system, drawing on groundwater to cool its facilities in summer and tapping stored heat in winter. The system can store enough heating and cooling capacity to meet the energy needs of roughly 2,000 single-family homes.
In the United States, Louisville Muhammad Ali International Airport runs a geothermal system built around 648 vertical wells, each about 152 meters deep. The geothermal field taps the ground's natural temperature to heat and cool the terminal, delivering roughly $400,000 in annual savings along with reduced emissions tied to climate control.
Another example is found at Geneva Airport in Switzerland. Its East Wing, used primarily for long-haul flights, incorporates 110 geothermal probes installed beneath the building. Connected to heat pumps, these probes provide heating in winter and cooling in summer. The building pairs this system with more than 7,000 square meters of solar panels and other high-efficiency systems.
There’s no single way to harness energy from underground, rather the right solution depends on a site’s geology, the size of the facilities, and their specific energy needs.
Spain also looks underground
In Spain, geothermal energy is already part of the toolkit used to improve energy efficiency at airport facilities. Reus Airport, in Tarragona, was the first to introduce a geothermal climate control system, using thermal energy from the ground to serve its fire and rescue service facilities.
The project, launched by Aena, was designed specifically to explore the potential of this technology throughout the airport network. During the study phase, researchers estimated the system could deliver energy savings of 50% compared with conventional air- and water-based systems.
Now, geothermal energy potential is being applied on a much larger scale. In June 2026, Aena announced a €14 million investment in a new geothermal installation at Adolfo Suárez Madrid–Barajas Airport. The project calls for up to 400 geothermal wells, each roughly 140 meters deep, connected to heat pumps and designed to generate renewable energy for climate control.
Beyond these individual projects, geothermal energy stands out as a renewable alternative that can be adapted to the specific characteristics and energy needs of any airport. Its ability to deliver stable heating and cooling, along with its potential to cut reliance on conventional systems, makes it a solution with real room to grow across infrastructure that's increasingly pushing toward more efficient models.
