Possible energy source

The sewage treatment plant should also provide heat in future

District heating will soon be generated at the sewage treatment plant.(Bild: Stadt Villach/ Thomas Künster)

The city and Kelag Energie und Wärme are examining the potential of wastewater for future district heating use.

The district heating network in Villach covers 130 kilometers. And 80 percent of the heat already comes from biomass and waste heat. In order to improve this figure and further expand the network, the city and Kelag Energie & Wärme (KEW) have been looking for new energy sources and have found a potential one in the wastewater from the sewage treatment plant.

The potential of the wastewater treatment plant to meet the heating requirements of the people of Villach is incredibly high.

Villachs Bürgermeister Günther Albel

The plant not only treats wastewater from Villach, but also discharges wastewater from surrounding municipalities. The plant is designed for 250,000 residents, making it one of the largest in Austria. "The potential to cover Villach's heating requirements is correspondingly large," says Mayor Günther Albel.

The city has therefore signed an agreement with KEW to exploit this potential. "Energy management and technical evaluations are currently underway." At the heart of the project will be heat pumps to extract the heat from the wastewater so that it can be used for district heating.

Possible detailed planning from 2026
"If the preliminary tests and the conceptual design with the city and those responsible for the wastewater treatment plant produce positive results, we can start detailed planning in 2026," say Adolf Melcher and Christoph Herzeg from Kelag Energie und Wärme. With this additional energy generation from the effluent, it will even be possible to achieve energy-neutral plant operation in future.