Geothermal Delft: geothermal energy and heat storage accelerate the heat transition

Start of Geothermal Energy Delft

On February 25, 2026, an important milestone was reached for renewable energy in the Netherlands. From this date, the Geothermal Delft project will officially provide geothermal energy to the TU Delft Campus and surrounding student homes. During a festive moment, the project partners celebrated this step together towards a more sustainable heating system.

In the coming years, around 6,000 homes in the Delft neighborhoods of Voorhof and Buitenhof will be connected to the heat network. In doing so, the project shows that geothermal energy can be a scalable and reliable source of sustainable heat for urban areas and existing homes.

For the Dutch energy transition, this means another important step towards a natural gas-free built environment.

Geothermal energy as a sustainable heat source for the built environment

In the Netherlands, geothermal energy has been used for a long time, especially in greenhouse horticulture. Geothermal Delft is special because geothermal energy is used directly for homes and buildings in an urban environment.

The heat from the deep underground is supplied to homes, student complexes and buildings on the TU Delft campus via a heat network. This reduces the use of natural gas and significantly reduces the CO₂ emissions of the built environment.

The project shows that collective geothermal heating systems are a realistic solution for sustainable district heating.

Innovation in geothermal energy: High Temperature Storage (HTO)

An important innovative part of Geothermal Delft is the application of High Temperature Storage (HTO). This technology makes it possible to temporarily store heat from the geothermal source in the subsoil.

In summer, when heat demand is lower, excess heat can be stored in shallower, permeable layers of the Earth. In the winter, this heat can be recovered when the heat demand is higher.

Through this form of underground heat storage:

• the efficiency of the geothermal source is increased
• the security of supply of the heat network increases
• the system can better deal with seasonal differences in heat demand

The HTO installation in Delft will be the first in the Netherlands to provide heat from storage to the built environment. In addition, the installation is part of the European research program PUSH-IT, which studies how energy storage can contribute to a more efficient energy system.

Research and knowledge development on geothermal energy

A unique aspect of Geothermal Delft is the close cooperation with TU Delft. The project is linked to scientific research into, among others:

• geothermal reservoir performance
• optimization of heat networks
• integration of geothermal energy and heat storage
• monitoring of underground energy systems

This combination of practical experience and scientific research accelerates the safe and responsible scaling up of geothermal energy in the Netherlands.

Thanks to the knowledge gained, future geothermal projects can be developed and applied more efficiently in other cities.

Collaboration as key to successful geothermal projects

Geothermal Delft was created through intensive cooperation between various public and private partners. The project is developed and implemented by:

• Gaia Energy
• TU Delft
• AND
• Net Verder
• In Warmth
• Municipality of Delft

In addition, housing associations Woonbron, Vidomes, Stedelink and DUWO play an important role in connecting homes to the heat network.

The sustainable heat is supplied to residents and buildings via NetVerder and heat supplier InWarmte. Trust, transparency and attention to affordability for tenants were important success factors in developing the project.

This public-private partnership shows that geothermal energy, heat storage and heat networks together form a feasible route to sustainable collective heat.

Gaia Energy: building sustainable heat in the Netherlands

Gaia Energy plays an important role in the development and realization of Geothermal Delft. The project is a concrete example of how cooperation between knowledge institutions, governments and energy companies can accelerate the energy transition.

By combining geothermal energy with innovative solutions such as heat storage, a robust and future-proof energy system is created.

With Geothermie Delft, we are not only building sustainable heat for today, but also knowledge, innovation and scalable solutions for the future of geothermal energy in the Netherlands.

Gaia Energy is proud of its contribution to this project, a tangible example of how geothermal energy can play a key role in the heat transition.

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