Press release • November 15, 2023
District heating company Fjernvarme Horsens A/S and Innargi A/S have entered into an agreement to investigate the possibilities of establishing geothermal energy for district heating. Fjernvarme Horsens requires heat for its expanding customer base, while Innargi anticipates that the subsurface beneath Horsens presents favorable opportunities for geothermal energy development.
Fjernvarme Horsens has tripled its customer base in ten years. In line with the city council’s goal to reduce the city’s carbon footprint by transitioning gas customers to district heating, the number of district heating connections has increased from 8,200 to over 22,000, with more expected.
”We need more green district heating in Horsens in the future, when we get even more new customers. It is important to utilize various heat sources to maintain a stable heat supply and attractive pricing for customers. Geothermal energy is an interesting option if the price is right.”
Clarification in a year’s time
Now, Fjernvarme Horsens and Innargi are working together to explore the potential. Innargi will perform comprehensive assessments of the subsurface. Jointly, the partners will determine how district heating users in Horsens can maximize benefits from geothermal energy, in conjunction with other available heat sources of the district heating company. Once the studies are completed, the partners can assess whether geothermal energy is the right solution for Horsens.
The parties aim to complete the studies and calculations during 2024.
“The geological data we have already reviewed suggest that the subsurface beneath Horsens is well-suited for geothermal energy. Additionally, this project has geographical ties to our major project in Aarhus and our collaborative development with the district heating company in Skanderborg. Therefore, I hope that together we can develop an attractive project for the district heating consumers in Horsens.”
Secure green district heating
Geothermal heating is a very climate-friendly heat source for district heating. Since the pumps in geothermal systems are driven by renewable energy from the sun or wind, geothermal energy is not only CO2 neutral but also emits no other harmful particles. And the geothermal heat source is always available – even when the sun isn’t shining and the wind isn’t blowing.
About the parties
Fjernvarme Horsens A/S provides stable, environmentally friendly, and cost-effective district heating to extensive areas of Horsens and its vicinity, playing a vital role in the city’s green transition. Fjernvarme Horsens prioritizes security of supply and stable prices and has therefore built up a diverse production portfolio. This portfolio includes various energy sources such as waste energy, biomass, electricity via heat pumps and boilers, local surplus heat, and natural gas. The intention is for the district heating produced to constantly become greener, which is supported by the current project. Owned by over 22,000 shareholders, the majority of whom have joined recently, the company is part of one of Denmark’s largest ever conversion projects.
Innargi specializes in financing, developing, building, and operating large-scale geothermal heating plants for district heating companies. The company is owned by A.P. Møller Holding A/S, ATP and NRGi.
Geothermal energy is the heat energy that comes from the earth’s interior. In Denmark, at depths of one to three kilometers, geothermal water ranging from 30-80 degrees Celsius exists in many areas. This water can be pumped to the surface through deep boreholes, transferring the heat to the district heating network’s water in a closed circuit. Once the heat is transferred, the geothermal water is pumped back underground. Depending on the underground temperature, it may be necessary to use large heat pumps to elevate the temperature to the required level for the district heating network.
While the potential for geothermal energy in district heating in Denmark is considerable, realizing this potential hinge on local subsoil conditions (adequate flow and temperature) and whether there are available areas near the district heating network. In addition, the Danish Heat Supply Act requires that geothermal energy is competitive with the alternatives available to district heating companies.