30 years of geothermal energy in Denmark

These days mark a milestone for one the most overlooked renewable energy sources: geothermal energy. It is now 30 years since the official inauguration of the geothermal plant in Thisted, Denmark, which continues to provide green district heating to Danish households.

The potential for geothermal energy in enormous, not least in Denmark. But gazing across the renewable landscape often overlooks this energy source in favor of more popular ones such as wind, bioenergy or solar power.

However, this does not diminish the potential of geothermal energy as a relevant source in the future Danish renewable energy mix, able to provide energy for district heating for as many as 300,000 households – and able to do so for many decades ahead – as the Thisted plant has already proved for 30 years. Furthermore, it is worth nothing that the district heating supply in Thisted has incorporated waste incineration, a straw boiler and even solar panels in addition to geothermal energy. Another interesting point is that district heating in this area belongs to the third cheapest in Denmark, according to price statistics from the Danish Energy Regulatory Authority.

The gap between numerous projects and few actual implementations can largely be explained by the lack of a national guarantee scheme in Denmark. So far, more than 10 projects have hit the wall at the exploratory drilling stage because of this, and up until today 2 geothermal plants exist, one in Thisted and one in Copenhagen, both providing energy for district heating:

“Geothermal energy holds massive potential. Around 300,000 households could be supplied by geothermal district heating. But this will not be realised unless it is prioritised by government, for instance through a national guarantee scheme, as is the case in France and the Netherlands,” explains Managing Director of the Danish District Heating Association Kim Mortensen.

A bit more about Danish geothermal energy
Geothermal energy is a renewable energy source with vast potential. It carries the benefits of low CO2 emissions, low running costs, local production and high security of supply. And after investments it has a long life. The geothermal reserves in the Copenhagen area in Denmark could cover 30-50% of the areas district heating needs for the next several thousand years.

In Denmark, low-temperature geothermal heat is used in district heating as one of many energy sources. The technology utilises energy obtained from porous sandstone beneath some Danish cities. There are currently two geothermal plants operating in Denmark (in Thisted and on Amager, Copenhagen).

Source: State of Green