The town of Flensburg in Schleswig-Holstein, northern Germany becomes the latest in a growing list of geothermal district heating projects of Danish developer Innargi A/S, after signing a letter of intent with local utility Stadtwerke Flensburg to investigate the geothermal potential of the area.
Flensburg is the second project of Innargi in Germany, after the signing of a similar agreement with Stadtwerke Kiel in March 2023. Innargi also has multiple geothermal heating projects in Denmark and another in Poland. The company is currently building the EU’s largest geothermal heating plant in Aarhus, Denmark.
The investigation will also include determining an optimal location for the potential deep drilling and integrating the heat into the district heating system of Stadtwerke Flensburg. Together with all other planned investigations, it will take about a year until all the necessary data is available. The project partners will then evaluate whether the Flensburg geothermal potential is sufficient to be able to produce enough district heating at a competitive price.
In principle, Innargi will be responsible for all exploration work and the construction of the geothermal heating plant and its operation as part of the project. Innargi also shoulders the investment costs and carries the risk for the well. Stadtwerke Flensburg can accept the climate-neutral geothermal energy for their district heating customers and feed it into their heating network, but they can also use cheaper heat sources at their own discretion.
“In our transformation path, we have stipulated that we will be climate neutral by 2035 at the latest. This does not happen overnight or with just one step but is based on many different building blocks. If it turns out that Flensburg’s underground has enough potential for geothermal energy, that would be a great contribution to our journey towards climate neutrality,” said Dirk Thole, Managing Director at Stadtwerke Flensburg.
“The Innargi team and I are delighted about this cross-border cooperation with Stadtwerke Flensburg. We are firmly convinced that geothermal energy will play an important role in the decarbonization of heat supply and we are proud to support Stadtwerke Flensburg on their journey towards climate neutrality. As a first step, we first need to find out what the subsurface conditions look like to assess whether the resources below Flensburg are sufficient for geothermal district heating generation,” added Hildigunnur Thorsteinsson, Chief Technical Officer (CTO) at Innargi.
