Swiss Alpine solar programme struggles to deliver

Only four of 30 planned Alpine solar projects are under construction, leaving Switzerland’s Solar Express far behind the pace set when parliament approved the programme four years ago. The initiative was designed to speed up large photovoltaic installations in high mountain regions and add electricity during the winter, when Swiss production faces greater pressure.

The first major project, Sedrun Solar in Tujetsch, canton Graubünden, is already feeding power into the grid. Nearly half of the facility has been completed, and its operator expects it to supply 6,500 households once construction finishes. The installation covers an area equal to 36 football pitches at an altitude of around 2,000 metres.

Its early results have strengthened the technical case for mountain solar. Last winter, the plant produced more electricity than expected. Bifacial panels capture sunlight on both sides, with reflected light from snow contributing as much as 20% of total production when conditions are favourable.

Sedrun’s progress, however, has not translated into a national construction wave. The slow rollout has forced federal authorities to reduce their forecast for Alpine solar’s contribution from around 3% to closer to 1% of annual electricity consumption.

Sedrun Solar depends on CHF 50 million in federal support, a contribution that shows both the scale of the investment and the difficulty of building in the high Alps. The project’s total budget is CHF 87 million, with the government covering up to 60% of the cost under the Solar Express framework.

The facility’s design targets a specific weakness in Switzerland’s electricity system. At high altitude, panels can receive stronger sunlight than installations in the lowlands, while snow can reflect additional light onto their rear surfaces. The resulting winter production could help reduce reliance on imports during colder months.

Ciril Deplazes, managing director of operator Energia Alpina, said the panels produce power from sunlight on both their front and back sides. When sunlight is weak, the rear side can still make a measurable contribution. During the previous winter, Sedrun generated more power than anticipated.

The project also illustrates the conditions required for Alpine solar to move forward. It needs a willing local authority, a viable grid connection, public acceptance and enough federal support to absorb construction risks. Other proposals have struggled to assemble the same combination. Sedrun’s success provides evidence that the technology can work, but it does not remove the financial and planning barriers facing projects elsewhere.

Valais has produced some of the strongest Alpine solar ambitions and some of the clearest signs of resistance. In Grengiols, in Upper Valais, developers planned Switzerland’s largest solar farm. The project has been scaled back after opposition from environmental groups, and it remains in public consultation. No panels have been installed.

A second proposal in the Val d’Anniviers has cleared its final planning stage, yet construction has not started. The project’s profitability remains uncertain, according to David Melly, the local mayor. He said current estimates put the costs relatively high compared with other forms of electricity generation and called for further optimisation.

These projects must navigate more than engineering questions. Alpine valleys are working landscapes, tourism destinations and habitats for plants and wildlife. Large installations can alter views, occupy pasture and trigger disputes over local land use. The approval process therefore brings municipalities, residents, environmental organisations, energy companies and cantonal authorities into the same decision.

The regional pattern also exposes an uneven national rollout. Of the four Alpine solar projects under construction, none is in French-speaking Switzerland. The gap does not prove that opposition alone is responsible for delays, but it shows how differently the programme is advancing across Switzerland’s mountain cantons.

Federal officials now expect Alpine solar to cover closer to 1% of Switzerland’s annual electricity consumption, down from an initial estimate of around 3%. Frank Rutschmann, head of the Renewable Energy Section at the Swiss Federal Office of Energy, said the projects had proved technically more difficult than expected.

Strong winds and heavy snow demand robust construction and regular access in terrain where work is difficult for much of the year. Grid connections can also sit far from proposed sites, adding infrastructure costs and extending the time needed to bring a plant online. Each issue affects the business case, particularly when electricity prices and construction costs fluctuate.

Rutschmann said the combination of weather, distance and engineering complexity had made the projects more expensive and time-consuming than planners anticipated. His assessment explains why a programme built around accelerated approvals has not produced accelerated construction at national scale.

The revised forecast also changes the role Alpine solar can play in Switzerland’s energy transition. Mountain facilities may still provide valuable winter output, especially when snow enhances bifacial panel performance. Their contribution will remain limited if project pipelines continue to shrink, approvals drag on or developers cannot secure economical grid connections. The policy challenge now extends beyond licensing speed to project design, finance and regional coordination.

Switzerland is putting more emphasis on rooftop solar as Alpine projects move slowly. Federal authorities say installations on homes and other buildings are expanding rapidly, with no sign of the growth losing momentum. Rooftop systems avoid many of the land-use conflicts associated with large mountain parks and can often connect to nearby electricity networks.

That shift does not make Alpine solar irrelevant. High-altitude facilities are designed to produce more in winter, a period when Switzerland needs dependable electricity and may rely more heavily on imports. Sedrun’s performance suggests that bifacial panels and snow reflection can deliver useful output in those conditions.

The question is how much capacity Switzerland can build at acceptable cost and with local consent. Solar Express has helped make Sedrun possible through substantial federal support, but the programme has not yet created a broad pipeline of construction. Grengiols remains under consultation, the Val d’Anniviers project is awaiting a start decision, and no project under construction lies in French-speaking Switzerland.

For households and policymakers, the immediate energy transition will therefore advance through several routes at once: more rooftops, selective Alpine projects and continued work on the grid. The federal government’s revised 1% forecast sets a more modest expectation for mountain solar than parliament received when it approved the initiative.