Geothermal energy has the potential to turn district heating energy greener, the same way wind energy has made power supply greener.

Large-scale development of geothermal energy is not yet deployed in Denmark, however considerable technical geothermal potential has been mapped in the country's subsurface.

In Denmark the reservoirs with geothermal potential are located between ca. 1,000 – 3,000 metres below the surface

The temperature of the reservoir water in the Danish subsurface is ca. 40 to 90 degrees Celsius

There are currently three minor geothermal plants in Denmark: Sønderborg, Copenhagen and Thisted

64% of all Danish households are connected to a district heating system

Today, geothermal energy makes up less than 1% of Denmark’s district heating supply

30% of Denmark’s district heating – the equivalent of 600,000 households – could be sourced from geothermal plants

Calculations show that with geothermal energy in district heating based on coal, an average household could reduce their CO2 footprint by 6 tonnes per year

Geothermal energy is already used in Paris, Lund, Munich and Italy’s Tuscany region

Geothermal energy for district heating is the fastest growing direct application of geothermal energy in Europe

Answers to some of the most frequently asked questions about geothermal energy

  • Are you gradually cooling down the subsurface?

    No. The water heats up again over time. Reservoir in the immediate area around the geothermal wells, a temporary cooling occurs, as the cold water is pumped back into the reservoir again. Accordingly, these geothermal wells typically have a life span of 25-30 years, after which new wells can be drilled a few kilometres away from the original location.

  • Will district heating companies have to pay more if geothermal heating ends up being more expensive than you anticipated?

    No. Our business model is structured in a way so that we take all the risk during the exploration, construction and operational phases. The district heating companies will not receive an extra bill from us if costs turn out to be higher than our initial assessment.

  • Will geothermal energy mean that our district heating will become more expensive?

    Our business model is built around the premise that we must be competitive when comparing ourselves to the other options available to district heating companies.

  • How will the location of the plants be determined?

    The location of the geothermal plants will be determined in cooperation with the relevant municipalities. We take several factors into account, such as the environment, nature, cultural considerations, drinking water sources, existing urban plans as well as the existing district heating infrastructure.

  • Will the construction of the plants be to the annoyance of the local residents?

    It takes about a year to establish a geothermal plant. During the drilling phase, which lasts 2-3 months, the neighbors to the construction site may experience nuisances such as noise, light at night and view to a drilling rig. We will seek to minimise any such nuisances by using, as far as possible, automated drilling rigs, that are less noisy, of less height and require less light compared to a standard rig. Where possible, the rigs will be powered by electricity. For the remaining nine months of the construction phase, the nuisance will consist primarily of increased and heavy traffic in the immediate area. We will seek to minimize traffic to the building site during the evening and night hours, and trucks and forklifts will use a non-noisy alternative to rear alarms during the night.

  • Will the geothermal plants be to the annoyance of the local residents?

    The plant takes up 700-800 m2, corresponding to a the penalty area in a soccer field. If the plant is located in an urban area, it will be partially buried below-ground and can – in consultation with the local municipality – be integrated in the surroundings, for example as a skateboard park or a recreational area. No noise is expected from the plant, nor will there be daily traffic on and off.

  • What does a geothermal plant look like?

    The plants are integrated into their surroundings and can be built either as an above-ground hall or partially buried below-ground. For example, they could be built in connection with a parking lot or by a field or recreational area. The placement and integration of the plant(s) that will be built in a specific area will be determined in close dialogue and consultation with the municipality, architects and local residents.

  • Does it pose any contamination risks to our drinking water?

    No. A geothermal well drilling is carried out in the same way as a drinking water well drilling, which protects the groundwater from contamination by using cemented steel pipes. These pipes isolate and protect the groundwater reservoirs from seepage from above as well as the geothermal water that is circulated through a closed loop. The plants are equipped with sensors and alarm systems that ensure that any leaks or errors are immediately discovered, making sure the plants are shut down before any damage can occur.

  • Will fracking (hydraulic fracturing) be required, as in shale gas drilling?

    No, we will not be using hydraulic fracturing in Denmark.

  • What is district heating composed of today?

    Danish district heating is composed of biomass (46%), natural gas (15%), coal (9%), biodegradeble waste (12%), waste (9%), Other renewable forms of energy, including geothermal (6%), oil (1%) and electricity (3%).

  • Can wind turbines be used to generate district heating?

    Wind turbines produce electricity, and the green electricity generated by wind turbines can be used by geothermal plants to generate district heating. In fact, this is an ideal combination.

Innargi A/S
Lyngby Hovedgade 85
DK-2800 Kgs. Lyngby

General inquiries

+45 32 26 88 00


Annette Henriksen, Secretary


Asbjørn Haugstrup

+45 26 72 94 21