Smart geothermal heat grid in Heerlen, The Netherlands

An example of Just Transition for coal mines with geothermal energy

The coal tunnels of Heerlen and its surrounding area in The Netherlands were flooded with groundwater when the mines were closed. This groundwater was naturally heated by the earth.

This geothermal source remained untouched for decades until 2005 when the municipality of Heerlen conducted a study to assess the possibility to use it to heat and cool buildings, homes, and offices. The rejuvenation started with a project supported by the European Interreg IIIB Programme and the 6th Framework Programme.

Now, Mijnwater B.V. is a rapidly expanding private company owned by the municipality, continuing to diversify and develop an innovative concept, the success of which has been proven over more than ten years.

The Mijnwater concept could be replicated in other former mining areas. In recent years, the technology has been further developed into a hybrid network, where the residual (unused) heating and cooling capacity from one customer is used for other customers, rather than wasted.

Heating temperatures are different according to the different needs. For instance, domestic hot water requires a higher temperature than space heating. A specificity of the Mijnwater Heating & Cooling network is that it makes very efficient use of energy by adjusting the temperature to the needs.

Mijnwater is the first thermal ‘smart grid’ for the supply of heating and cooling water in Europe. The reputation of the project is growing as it develops into a responsive system, altering supply biased on a number of demand-side factors, including the weather and customer demand, and synchronising with other renewable energy sources.

Heerlerheide Centre, Heerlen – photo courtesy: Mijnwater B.V.

  • Transformation of coal mines into district heating system fed with renewables
  • Energy and emission savings