Going underground – Netherlands geothermal heat revolution

The Netherlands is currently ramping up the development in geothermal energy. A new Heat Act has opened up opportunities for more and larger collective district heating networks, which need fossil-free energy sources. At the moment around 150 new heat projects are in development round the country. Geothermal heat – where wells are drilled two to three kilometres into the ground and heat from the Earth’s interior is used for heating production – plays an important role in that development. 

“From 2030 onwards, we need to meet the conditions for maximum CO2 emissions set out by the Heat Act. That means that in some heat networks, where we have many fossil-based sources, we need to replace those with sustainable sources. And we need to do it very fast,” says Ivo Vos, Project Developer at Vattenfall. 

At present, only 11.2 per cent of homes in the country are heated by something other than gas. Geothermal heat, together with sources such as waste heat from data centres, is expected to help increase that figure in the coming years. 

“Performs extremely well”  

Vattenfall is currently running four geothermal projects in the Netherlands, in several cases in collaboration with the state-owned energy company EBN, which has been involved in twelve different geothermal projects from 2019. EBN also runs the so-called SCAN project, in which they investigate and analyse the subsurface to make it easier for companies that later drill the wells. The results of SCAN are accesible to all geothermal projects in the Netherlands, such as the projects Vattenfall is working on Amsterdam en Almere.  

Michiel Houwing, Director of Heat Transition at EBN, sees many advantages to geothermal heat: 

“In terms of the carbon emitted per amount of heat delivered, geothermal performs extremely well. The same is true for the levelised cost of heat that can be provided. It is still a heavily subsidised technology, but nevertheless, with the subsidy, an acceptable tariff can be offered to the end consumer.” 

At work on geothermal energy in the Netherlands, where heat from deep underground could play a growing role in district heating. Photo: EBN/SCAN

Providing for heat networks 

The Netherlands has very favourable conditions for geothermal heat. The sandstones in the subsurface are more porous than the bedrock found in, for example, northern Europe, making it more economically viable to produce hot water from drilled wells, which are often several kilometres deep. Somewhat paradoxically, the Netherlands’ history of greater dependence on fossil fuels may actually work to its advantage. 

“To find the right geothermal locations, we have to understand what the subsurface looks like. Thanks to the Netherlands’ history of oil and gas production, we generally have a good understanding of the subsurface. In and around former oil and gas areas, where seismic data has already been collected, we can make use of that existing data,” Vos explains. 

Many of those areas have seismically been outside the urban areas where the geothermal heat sources are most needed to provide for the heat networks. The Scan project was created in part to fill in those blind spots in the subsurface knowledge. 

Energy Independence 

For the Netherlands, geothermal heat could provide a double benefit. It would make the country less dependent on predominantly foreign sourced gas for heating, while geothermal heat, which has a naturally high temperature from the outset, requires less additional energy from heat pumps. For a country with an electricity grid that is under almost constant strain, geothermal heat could therefore offer an important advantage. 

“District heating in general, and geothermal heat in particular, allow us to postpone investments in the electricity grid. If everyone in the Netherlands installs and uses heat pumps, it will place enormous pressure on a system that is already under strain. Although heat pumps will sometimes be needed in geothermal heating systems, their impact on the grid will be smaller,” says Houwing. 

There is also, Houwing continues, an aspect of energy independence. 

“Geothermal is a source that makes you less dependent on imports of other energy sources. Geothermal is extremely local, and that makes us less vulnerable. I think that is very important for the country as a whole, and of course also for the energy system. It makes the system more robust.”