The 3,000-meter depth was supposed to produce a lot of heat, but the result was a huge fiasco: “The most expensive hole in the world”

In 2010, an ambitious project was launched in Denmark to build a 32-megawatt geothermal district heating plant. The project, which has since failed, has led to years of legal disputes.

Drilling began in January 2012 in Kvols, Jutland, near the city of Viborg. The aim was to drill to a depth of about 3,000 meters and reach a geothermal water reserve, the temperature of which was estimated at about 73–75 degrees Celsius, the ThinkGeoEnergy website, a specialist in geothermal energy, reported in 2012.

According to the plan, the heat from the geothermal water would have been transferred directly to the district heating water using heat exchangers without the use of heat pumps. The plant was intended to provide heat for about 16,600 households.

However, not everything went according to plan. The drilling had reached a depth of just over 2,000 meters when the district heating company Viborg Fjernvarme decided to abandon the project in 2012. The company estimated that it was no longer sensible to continue drilling deeper.

At that time, 156 million Danish kroner had been spent on the project, or about 20.9 million euros at the current exchange rate.

The case has now been reported by the Danish technology media Ingeniøren, which refers to a recent article in the local newspaper Viborg Stifts Folkeblad.

According to Viborg Fjernvarme’s customers, the costs of the failed project have unjustifiably ended up as part of their district heating bills. The dispute concerns a total of 165 million Danish kroner, or about 22 million euros, and the case is now proceeding to the Danish Supreme Court.

The case has been handled at several levels of authority and court over the years. Most recently, in September 2025, the Supreme Court of Western Denmark rejected the customers’ claims for damages and acquitted the former management of Viborg Fjernvarme of liability.

The ground collapsed during drilling

The project encountered serious technical difficulties. Some of the expensive drilling equipment was lost in the borehole.

Lars Andersen, CEO of Ross Engineering, which led the drilling project, told Ingeniøren as early as 2012 that the drilling had encountered unexpected problems.

The shale layers above the water-bearing layers turned out to be more unstable than expected and collapsed during drilling.

“It creates a hole that is far too big and difficult to work with. We would have really liked to have known this in advance,” he told the newspaper in 2012.

The project, which has suffered from major budget overruns, has been called “the world’s most expensive hole,” according to Ingeniøren.

According to Ingeniøren, Lars Toft Hansen, former chairman of another district heating company, Thisted Fjernvarme, has told TV Midtvesti that the project’s problems were due to the slanted drilling. According to him, the project would have been successful without major difficulties if it had been drilled straight.