Green milestone for Denmark: Geothermal drilling has started in Aarhus

Green milestone for Denmark: Geothermal drilling has started in Aarhus

Press release • November 20, 2023

Standing 31 meters tall, this rig is set to drill 2.5 km into the earth to extract hot water. Today marks the start of the drilling work for the EU’s largest geothermal district heating plant, being constructed by Kredsløb and Innargi in Aarhus. Over the next few months, the rig will drill the first well to provide green district heating to Aarhus residents. The board chairman of Kredsløb, Finance Minister Nicolai Wammen, Mayor Jacob Bundsgaard, and Denmark’s Nature Conservation Association unanimously acknowledged this as a key milestone for Denmark’s green transition during the event at Aarhus Harbour.

It’s a spectacular sight greeting visitors at Aarhus Harbour in the coming months. A robust 6000-horsepower drilling rig has been set up to penetrate 2.5 km into the ground. And this is good news for the green transition in Denmark.

This drilling is part of setting up the EU’s largest geothermal district heating system, comprising seven sub-plants around Aarhus. Heat delivery is scheduled to begin in 2025. Upon completion of all sub-plants, the system is projected to provide 20% of Aarhus’s district heating.

“Today is a significant day for Aarhus and Denmark’s green transition as we move from planning to action, initiating drilling to provide Aarhus’s first geothermal district heating by 2025. When the facility is completed, it will be a key element in securing the stable and green supply of the future and a significant contribution to the city achieving its climate goals in 2030.”

Thomas Rand,

Chairman of the Board, Kredsløb

“It is fair to say that a piece of green Danish national history is written in Aarhus today. The Parliament agreed on the regulatory framework needed, and now we are putting the drilling rig to work. If we want to succeed with the green transition, we must make use of all available solutions. Geothermal is truly exciting in this regard. Today is a good day, and I look forward to following the project going forward.”

Nicolai Wammen,

Minister for Finance

Geothermal energy is poised to aid Aarhus in achieving CO2 neutrality by 2030

Geothermal energy, the extraction of hot water from underground, is a renewable and reliable energy source available daily, throughout the year.

When geothermal heating is combined with renewable energy from the sun or wind, it is both CO2-neutral and emission-free.

“Aarhus aims to be CO2-neutral by 2030, and the provision of heat to its citizens and businesses plays a significant role in this endeavor. It’s fantastic that we’re now taking the initial tangible step in this ambitious green project.”

Jacob Bundsgaard,

Mayor of Aarhus Municipality

First heat expected by 2025

The geothermal plants in Aarhus must be located close to the existing exchange stations, which send the district heating out to the homes in Aarhus. This means that in the coming years, many residents of Aarhus will find themselves living near one of the well-drilling sites.

While a geothermal plant does not produce noise or emissions once operational, neighbours may notice the noise from the drilling rig during its operation. In the coming months, this will be the experience of neighbours at Aarhus Harbour.

The drilling rig will work for a few months on the first well. Once the drilling rig is started, it works around the clock. An electric rig is used in the project, and noise walls have been established around the site to reduce noise nuisance.

Once drilling is complete on Sumatravej, the rig will move to Skejbyvej to drill wells there. The first wells also have the task of clarifying that, as expected, there is hot water in the subsurface meets the criteria for establishing geothermal district heating. The first facility, located in Skejby, is expected to be completed and start delivering heat to Aarhus residents in 2025. The facility on Sumatravej is expected to be completed in early 2027.

“If we are to reach our green ambitions, we must work with projects that really matters. Geothermal energy is a prerequisite for us to reach the goal of phasing out wood pellets by 2030 and thus become even greener in Aarhus. This is a significant milestone for us as a city. I also hope this project inspires other cities, demonstrating viable paths toward greener heating solutions.”

Nicolaj Bang,

Councilor for Technology and the Environment, Aarhus Municipality

Greener district heating on the way

With the facility in Aarhus, it will be possible for Kredsløb to reduce the amount of wood pellets that must be imported by 55,000 tonnes per year. This will reduce direct biogenic CO2 emissions by 95,000 tonnes. Moreover, utilizing the spared biomass for, say, methanol production for transportation could save an additional 70,000 tonnes of CO2, equal to the emissions from 30,000 petrol vehicles.

The company Innargi A/S is responsible for building the Aarhus facility for Kredsløb. The company was founded in 2017 and is today owned by A.P. Møller Holding, ATP and NRGi.

”We have wholeheartedly supported the establishment of geothermal energy from the outset. We’re not just introducing a new, large-scale renewable energy source. We are also developing a very real alternative to burning biomass, which neither emits CO2 nor affects biodiversity.”

Sebastian Jonshøj,

Vice-President, Denmark's Nature Conservation Association

“Geothermal has enormous potential in both Denmark and Europe, because it is an important part of the answer to how Denmark and Europe succeed in getting rid of Russian gas, phasing out coal and ensuring a green conversion of the heat supply at the same time. The start of drilling in Aarhus marks for us an important milestone on the way to realizing the potential of geothermal energy in Denmark and in Europe.”

Samir Abboud,

CEO at Innargi

Facts about the drilling work and the facility in Aarhus

  • The drilling rig was delivered in smaller parts on lorries and assembled on-site.
  • The drilling rig, which is electrically powered, stands approximately 31 meters tall and boasts 6000 horsepower.
  • Aarhus’s geothermal heating plant will become the largest in the EU, with a total capacity of 110 MW.
  • The first heat will be delivered in 2025 and all seven sub-plants will be completed in 2030
  • Geothermal energy is projected to fulfill 20% of the district heating requirements in Aarhus.
  • In Aarhus, geothermal energy is expected to reduce annual CO2 emissions by approximately 165,000 tonnes (a reduction in immediate biogenic emissions and a further reduction from the alternative use of biomass).
  • The initial drilling efforts aim to verify the underground’s potential to meet the criteria for establishing geothermal district heating.
Learn more about geothermal energy

About the partners  

Kredsløb supplies district heating to 330,000 people and recycles waste for 170,000 households in Aarhus Municipality. Kredsløb has a stated goal of making it easy for customers and business partners to contribute to the green transition.

Innargi was founded in 2017 by A.P. Moller Holding and is today owned by A.P. Moller Holding, ATP, NRGi, and Sampension.  Innargi’s mission is to bring clean, reliable district heating to Europe through the renewable resource in the subsurface– geothermal energy.

For further information, please contact:

Anders Rasmussen, Press Officer at Kredsløb, (+45) 2557 7809 /[email protected]

Louise Blaabjerg Christoffersen, Communications Lead at Innargi, (+45) 6025 8639 / [email protected]