The “District Heating Lower Wiggertal” (FUWI) project is making progress: Primeo Energie and StWZ Energie AG (the public utility of Zofingen) plan to establish a joint company in the second half of 2025 to expand and operate the district heating network in the Unteres Wiggertal. The energy suppliers of the municipalities of Oftringen and Rothrist have decided not to participate in the new company at this time.
Regional energy providers have been working together for some time on planning the expansion of the district heating network in the Unteres Wiggertal. Various studies have confirmed the potential of climate-friendly district heating. The FUWI project aims to give parts of the municipalities of Aarburg, Oftringen, Rothrist, Zofingen, and Strengelbach increased access to district heating in the future.
Establishment of a new district heating company
In autumn 2025, Primeo and StWZ plan to establish a new district heating company that will drive the expansion forward. Both partners will contribute their existing networks to the new company. Initially, the plan is to expand the district heating network in Oftringen and Zofingen, integrating the existing networks in both municipalities.
“The project is an important step towards decarbonizing heat supply. StWZ and Primeo are convinced that the district heating network in the Unteres Wiggertal can be implemented most effectively if we join forces with StWZ in a joint company,” says Michael Schneider, CEO of Primeo Wärme AG.
EW Oftringen AG (EWO) and EW Rothrist AG (EWR) have chosen not to participate in the new district heating company for different reasons. Due to its current equity situation, EWO is not in a position to make the necessary financial commitment.
The needs of EWR and the municipality of Rothrist are not yet met by the new company’s current direction. Additional clarifications and agreements are required. However, both companies support the regional expansion of district heating, and future participation remains a possibility.
Heat supplier: Waste incineration plant
The renewable heat will come partly from StWZ’s current energy plants, which primarily generate heat from wood, and partly from the erzo waste incineration plant (WIP) in Oftringen. Starting in summer 2027, the heat supply from the WIP will be increased to serve customers in Oftringen and Zofingen. If the erzo WIP project and the construction of the new plant proceed as planned, the network could also be expanded to Rothrist, Aarburg, and Strengelbach.
A key factor in this development is the approval of Oftringen’s voters in November 2025 regarding the rezoning of the required land. “We are committed,” explains Paul Marbach, CEO of StWZ Energie AG, “to offering customers in our region a climate-friendly district heating solution for heating system replacements in the coming years.”
Press Contacts
Primeo Energie
Viktor Sammain, PR Editor, 061 415 41 08, presse@primeo-energie.ch
StWZ Energie AG
Paul Marbach, CEO, 062 745 32 14, p.marbach@stwz.ch
EW Oftringen AG
Peter Woodtli, Chairman of the Board, 079 378 61 74, peter.woodtli@bluewin.ch
EW Rothrist AG
Ralph Ehrismann, Chairman of the Board, 079 785 36 36, ralph.ehrismann@rothrist.ch
