Published on 25 November 2025
Geothermal energy is the heat stored beneath the earth´s surface, a resource shaped by the planet´s formation and the natural decay of radioactive isotopes underground. It´s a natural resource that is renewable, constant, and reliable, offering a stable source of energy.
There are different ways we can harness it:
- High- and medium-enthalpy geothermal systems, which use high temperatures (above 80 °C) to produce electricity or supply district heating networks through deep aquifers.
- Shallow or very low-enthalpy geothermal systems, which rely on the thermal stability of the first 10–20 meters below ground. Through heat exchangers and reversible heat pumps, they can cool and heat buildings with extraordinary efficiency, in every season.
This second way offers technology that is driving the energy transformation of our cities, thanks to the ability to seamlessly integrate these systems into almost any urban environment, with minimal land requirements and without leaving a visual impact.
Bringing geothermal energy into the fabric of the city
At Ayesa, we are driving forward geothermal solutions that tap into the grounds stable temperature to deliver maximum-efficiency climate control for buildings. Our goal is to transform the subsoil and the structures of the city itself into renewable energy sources, reducing emissions, lowering electricity consumption, and reducing depending on fossil fuels.
This vision aligns with European decarbonization plans, such as the Net Zero Cities initiative and the Zero Europe strategy, which reinforce the EU´s commitment to reach climate neutrality by 2050. Shallow geothermal fits naturally into this mission, acting as a key technology for cities that want to be resilient, climate-adapted, and capable of ensuring a secure and stable thermal supply, even in periods of energy stress.
With our extensive experience in shallow geothermal systems, we´re able to support public administrations, developers, and urban managers in deploying sustainable and resilient thermal networks built to withstand the future.
Leaders in shallow geothermal and thermoactive infrastructures
As pioneers in designing and sizing geothermal systems embedded within civil works and buildings, we’ve delivered standout projects where reinforced concrete structures, including base slabs, diaphragm walls, and piles, become heat exchangers. This approach makes use of planned structural surfaces and eliminates the need for additional installations.
Our work with thermoactivated base slabs spans projects such as the A-5 undergrounding in Madrid and the extension of Metro Madrid’s Line 5, where structural slabs or columns incorporate embedded hydraulic circuits to transfer energy with exceptional thermal reliability.
With diaphragm walls, we’ve developed solutions that transform retaining structures into high-surface vertical exchangers, optimizing thermal performance in dense urban areas with limited space.
Our technical expertise covers every stage of the process: geotechnical and geothermal characterization, climate analysis, modelling, and exchanger design tailored to specific thermal demands. Mastering the interaction between soil, structure, and energy allows us to deliver systems that are robust, efficient, and compatible with any type of building.
An opportunity to build sustainable, future-ready cities
As Euope moves towards a clean, secure, and resilient energy system, shallow geothermal emerges as a strategic ally. Its ability to supply heating and cooling year-round positions it as an essential tool for cities striving for climate neutrality, aligned with the European Green Deal and the 2050 net-zero trajectory.
The combination of energy efficiency, climate resilience, and thermal stability makes this technology a cornerstone for designing cities that can adapt to global warming, reduce emissions, and strengthen their energy independence.
At Ayesa, we´re committed to making geothermal energy part of the urban blueprint of tomorrow, embedding renewable energy directly into the heart of our infrastructure.
