Experts assess whether heat from a spoil heap in Ostrava could be used for heating in Czechia

State-owned company Diamo, Veolia Energie and VSB–Technical University of Ostrava (VŠB-TUO) are assessing whether heat from the burning Heřmanice spoil heap in Slezská Ostrava could be used, for example, to heat nearby homes. Experts will monitor underground heat flows using a research borehole fitted with a coaxial heat exchanger. Representatives of the companies and the university told journalists this after using a crane to lower the exchanger into the 14-metre-deep borehole today.

Diamo staff prepared the research borehole at the top of the spoil heap. Václav Dorazil, deputy director of Diamo’s Odra plant, said the largest spoil heap in Ostrava reaches temperatures of up to 800 degrees Celsius beneath the surface.

The idea is to use the heat from the spoil heap by installing a vertical underground heat exchanger that would transfer heat from the burning spoil heap to heating water. This could then be used as an alternative for heating and hot water in nearby buildings. The pilot project will test whether this could work.

„We are standing on a spoil heap that is thermally active. It has been releasing heat for many years and will continue to do so for many years, which is why we are carrying out this research project. We want to use the data to establish whether it could be commercially viable in the future. And, given that we are also dealing with an environmental burden here, contributing to its resolution makes sense for us,“ said Tomáš Groň, director of ecological transformation at Veolia Energie.

The parties involved will decide on the next steps based on the results from the experimental borehole. „Our aim is to obtain basic data, because no one has looked into this at this level before. We will gather the data and then decide with our partners whether it is viable. Our aim, of course, is to find a way to use the heat for district heating and domestic hot water,“ Groň said.

The borehole has an output of up to 30 kilowatts, enough to heat two small houses. The measurement results are due to be analysed by the end of the year. If the project continues, boreholes could be drilled deeper, and output could also be increased by drilling more boreholes.

„If the temperature is high enough and remains so for a longer period, it could be used to heat a larger building. There is an industrial site here, with some buildings, and a prison a little further away, so we could potentially supply heat to them in some way. If it proves feasible to do this on a larger scale, more buildings could be connected,“ said Bohumír Čech, a member of the Department of Energy at VŠB-TUO.

Dorazil said the Heřmanice spoil heap covers about 103.5 hectares and contains an estimated 30 million tonnes of material. It consists of spoil and waste from former mines and coke plants. It is one of the oldest and largest sites containing spoil from hard coal mining in the Ostrava region during the 19th and 20th centuries. The spoil heap has been burning underground for decades, releasing harmful substances into the air. Its remediation has been underway for more than 15 years, and the new project will not affect its progress.