Geothermal heat

Geothermal heat is the collective term for heat that occurs from the deeper layers of the ground. With a geothermal heat pump, hot water is pumped up and used for various heating processes. Due to the large availability of hot water from the underground, geothermal heat is an almost inexhaustible source of energy.

In this article you will read all about geothermal heat in the Netherlands. For example, we discuss where it is applied, how a project is developed and when it is profitable.

Where is geothermal heat applied?

There are currently more than 20 geothermal projects (aardwarmteprojecten) active in the Netherlands, many of which are used for greenhouse horticulture. Most of the projects are in the South Holland area, where hot water is extracted (and cooled water is injected again) from rock strata from the Cretaceous period. Those layers are about 2,000 meters deep.

Where are the opportunities for geothermal energy?

Besides South Holland, there are a number of other locations in the Netherlands with rock layers that are suitable for geothermal energy (geothermie). In the northern Netherlands, the greatest opportunities lie in the Permian-period rock strata (for example, the 'Rotliegend' or the 'Slochteren formation'). Projects in Kampen and Middenmeer are already producing hot water from these.

In Limburg, heat is produced from rock strata from the Carboniferous period. These are relatively shallow here compared to other places in the Netherlands.

Throughout the Netherlands, operators of geothermal wells must ensure that their activities do not lead to seismic activity in the subsurface. This is monitored by State Supervision of Mines.

This is a specific concern for the projects in Limburg because this is also a tectonically active area. This means that natural earthquakes occur.

Geothermal heat from rock strata

In many places in the Netherlands the rock strata from the Carboniferous are much deeper. We are currently looking into the possibility of extracting geothermal heat from these layers. Because of the deep location, the temperature of the water will be much higher. This is favorable for all kinds of industrial applications. The feasibility will ultimately depend on the amount of water that can be produced from the rock at that depth.

In addition to these known rock layers, there are other rock layers that may be suitable because they lie deep enough and have good permeability. For example, the "Brussels Formation," a rock layer of permeable sand, lies relatively shallow. It has a low temperature, from 25-45°C, but could potentially still be interesting because the cost is relatively low compared to deeper geothermal energy.

The distribution of these layers in the Netherlands is sometimes limited. The possibilities will have to be considered on a case-by-case basis. In many places in the Netherlands, the possibilities are still relatively unknown because there is too little geological data available. A national program is currently underway to map these 'white spots'.

When is geothermal heat profitable?

Successful geothermal projects are those in which the heat demand and heat supply are well matched. Heat demand is usually not stable throughout the year. Geothermal heat can be produced continuously and can thus fill the basic demand for heat.

Virtually all geothermal projects will need to have a backup system (CHP, boilers, biomass plant (biomassacentrale)) to handle peak loads. This must be considered in the project design.

Geothermal development process

Before a geothermal heat project can be realized, the local opportunities and constraints must be properly identified.

This will have to include both underground and above-ground aspects. This is because the possibilities depend greatly on the type of project. For example, there is a clear difference between applications for single consumers of heat, such as for a group of market gardeners, and applications in the built environment, where the geothermal source is one of the heat sources in an open heat grid.

A large part of the geothermal projects realized so far in the Netherlands are related to horticultural companies. In half of these projects, Ekwadraat has supervised the application for subsidies and various permits (exploration permits and environmental permits).

To realize a geothermal source, the following roadmap is generally followed:

Built environment

Applications in the built environment are often more organizationally complex due to the different roles of:

  • Governments
  • Grid operators
  • Customers
  • Energy companies

Decision-making processes are also different for these projects. This must be taken into account in the planning.

The risks are often different in these types of projects, partly because the investments and civil-engineering implications of the infrastructure are often greater than those on the generation side. This while the technical-geological risks at the beginning of the project often do determine the success of the project.

Realizing geothermal heat pump

Ekwadraat has a good understanding of geographic variation and can help identify the potential of geothermal heat for you. We know the geological risks and can help you evaluate projects from a portfolio approach.

Until now, work has mainly been done from project to project. As a result, the risks always lie with each individual project. With a portfolio approach, on the other hand, it is possible to accelerate the development of geothermal energy in the Netherlands. Ekwadraat can help you, based on its network and knowledge, to arrive at a well-considered decision for a portfolio construction.

Ekwadraat has the experience, the knowledge and the network to help every geothermal project move forward. This knowledge is mainly in:

Ekwadraat guides you during the preliminary phase, but also when the project is already underway. Please contact us for an informal discussion.  

Ekwadraat in figures


Involved in 50% of all geothermal projects


11+ years experience


Familiar with all parties involved


Leading projects

Would you like help with the realization of a geothermal project?

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"I would love to help with your geothermal heating project!"

Ruud van Aart

Adviseur SDE subsidie & energietransitie