Aventron, a subsidiary of Primeo Energie, has launched the jointly operated Sidenplangg alpine solar project in partnership with energieUri AG in Spiringen (UR). The electricity generated will also be supplied to Primeo Energie and the other shareholders of aventron.
On July 2, 2025, construction of Central Switzerland’s first alpine solar power plant was officially inaugurated with a groundbreaking ceremony in Spiringen, canton Uri. While construction has been underway since April, the ceremony marks the formal launch of the "Sidenplangg" project—developed as a joint venture between aventron, a subsidiary of the Primeo Energie Group, and local utility energieUri AG. To manage the project, a dedicated company, APV Sidenplangg AG, has been established. The first ten percent of the facility is expected to go online later this year, with full completion planned by 2028.
Clean electricity for over 2,600 households
The plant will have a capacity of 8 megawatts and produce approximately 12.5 gigawatt-hours of solar electricity annually—enough to supply around 2,600 average households. A key focus is on improving winter supply security: due to its higher elevation, colder temperatures, panel orientation, and snow reflection, solar efficiency in alpine environments is particularly high during the winter months.
Broad-based energy offtake by Primeo Group and its partners
Primeo Energie, along with fellow aventron shareholders Energie Wasser Bern (ewb) and Stadtwerk Winterthur (SWW), will purchase a share of the solar power generated at Sidenplangg. "This project is an excellent example of meaningful collaboration between the mountain cantons and the Swiss Plateau," says Cédric Christmann, CEO of Primeo Energie. "It gives our customers access to more green electricity, especially during the critical winter months. At the same time, we and our partners are making a tangible contribution to Switzerland’s energy security and independence."
A project with pioneering character
Alpine solar energy plays a central role in Switzerland’s Energy Strategy 2050. The Spiringen plant is the second high-altitude solar facility in which aventron is involved. Since late 2024, the company has also been developing a similar project in Sedrun in partnership with energia alpina. These initiatives make aventron and its partners leaders in the field of alpine solar power generation.
Press contact
Viktor Sammain, PR Editor
Direct line: +41 61 415 41 08
Email: presse@primeo-energie.ch
