Slovak Mochovce nuclear power plant plans to launch district heating within three years

Slovakia’s Mochovce nuclear power plant is expected to start supplying heat to the nearby town of Tlmače within three years. As part of a renovation of the central boiler house in the town, which has around 3,500 residents, the biomass- and gas-fired boilers will be replaced. The power plant plans to supply more than 6 GWh of zero-emission heat a year for the town’s heating system.

Slovenské elektrárne announced that, as part of efforts to make greater use of the Mochovce nuclear power plant’s energy, it will focus on supplying heat to the town of Tlmače. The project is at the stage of selecting a technical solution and assessing its economics.

The power plant plans to divert some heat from a unit’s secondary circuit, from which the town could take 6.3 GWh (around 22.5 terajoules) of waste heat a year. Connecting to the district heating system in Tlmače will also require the construction of a pipeline around 6 kilometres long. As part of the renovation, the town’s district heating operator plans to install water-to-water heat pumps to supplement the heat supplied by the power plant.

"The project’s technical solution involves connecting to the cooling-water circulation loop pipeline and building a heat exchanger station. Circulating water at a temperature of 25-36 °C will transfer its heat through a plate heat exchanger to a closed secondary circuit," Slovenské elektrárne said.

If all goes well, Slovenské elektrárne expects construction to begin in 2027, with heat supplies starting in early 2028.

Zero-emission heat for households

The town, which has just over 3,500 residents, currently relies on a central boiler house with biomass- and gas-fired boilers, so the new heat source would significantly reduce the carbon footprint of heating. Slovakia’s other nuclear power plant, Jaslovské Bohunice, has been supplying heat to nearby towns and villages since 1987. In 2023 alone, it supplied 429 GWh (860 TJ) of heat.

Czechia’s Temelín nuclear power plant also began supplying zero-emission heat in 2023. Around 210 GWh (750 TJ) of heat flows each year through the 26-kilometre heat pipeline to České Budějovice. Czechia’s other nuclear power plant, Dukovany, is still planning to start supplying heat to Brno, around 40 kilometres away. Construction of the heat pipeline is scheduled to begin in 2027 and is expected to take 4 years.