Winterthur is strengthening security of supply with new energy solutions
In the 2025 financial year, Stadtwerk Winterthur generated CHF 36 million, around CHF 10 million more than in the previous year. This is attributed to low temperatures and favourable energy procurement. Meanwhile, the expansion of renewable energy is progressing.
With total turnover of 293 million Swiss francs and an operating profit of 36 million Swiss francs, Stadtwerk Winterthur has closed the 2025 financial year with strong growth. Although turnover in 2024 stood at 311 million Swiss francs, the profit of 26 million Swiss francs was lower than in the following year. According to a press release, one reason for the increase in 2026 was the cold weather at the start and end of the year, whilst another was that Stadtwerk was able to purchase gas on favourable terms. The positive result was also boosted by the fact that a stake in renewable energy production had increased in value.
The current annual report states that the year was heavily influenced by the implementation of the new electricity legislation. This aims to expand renewable energy and strengthen security of supply. This includes the formation of local electricity communities (LEG) as well as two new long-term contracts relating to high-altitude solar power from the large-scale Sedrun Solar and Sidenplangg plants.
Described as the first solution of its kind in Switzerland, a seasonally dependent feed-in tariff model was adopted in 2025 and has been in force since the start of this year. It is intended to enable producers with their own solar power systems to optimise their consumption.
The strategy to reduce the share of natural gas and expand district heating networks is reflected in the refurbishment of the waste-to-energy plant, for which a planning application has now been submitted. Furthermore, the wastewater treatment plant is to be refurbished and expanded. Voters will decide on the investment of 293 million Swiss francs on 14 June.
The electrification of many sectors also led to increased electricity consumption and a higher load on the grid for Stadtwerk 2025. As a direct response, the Tössfeld and Grüze substations in Winterthur were upgraded.