A vote on Sunday saw Swiss voters reject plans to fund and accelerate large solar power projects on mountainsides.
Voters in a southern Swiss region have rejected plans to allow large solar farms to be constructed in the Alps.
The proposal was part of the federal government’s push to develop renewable energy sources.
The referendum, held in the Valais canton on Sunday 10 September, centred on economic and environmental interests at a time of high and rising concerns about climate change.
The canton wrote on its official website that almost 54 per cent of people voted against the proposal. Turnout was almost 36 per cent.
Why did Swiss citizens reject plans for Alpine solar parks?
The vote was a noteworthy test of public opinion. It also made for some unusual political allies, with some environmental groups aligning with Switzerland's conservative populist party on certain points.
They had said solar parks would be an industrial eyesore on pristine Swiss mountains.
They argued that outfitting more buildings and homes in towns and cities - closer to where the energy would be used - is preferable.
“Through its giant dams, Valais has already given a large share of its electricity to the country,” the local chapter of the Swiss People's Party said on its website. “Adding another environmental degradation to this first one is unacceptable.”
“Ransacking our Alps for the benefit of greedy foreign operators and their no-less-greedy local affiliates can only be an evil enterprise and be to our detriment,” it added.
The Valais Green Party and environmental organisation Pro Natura - who jointly launched the referendum - also argued that the plans didn't properly take the impact on nature and wildlife into account.
On calling the referendum in February, Pro Natura said that it "considers that a solar offensive is necessary, but not to the detriment of wild Alpine spaces."
It urged projects to focus on "largely underexploited" existing infrastructure such as dam walls, storage lakes, avalanche barriers and roads instead, highlighting Switzerland's high proportion of endangered species.
Alpine solar parks could help provide renewable energy in winter
Proponents had said Switzerland benefits from hydropower - its main source of energy - mostly in the summer.
High-altitude solar parks situated above the typical cloud cover would provide a steady, renewable-energy alternative in the winter, when the country needs to import electricity.
They said that federal funding would have sped up development of solar power on sun-baked Alpine mountainsides.
Valais lawmakers and officials had been urging a 'yes' vote on the proposal, which asked voters to agree to a decree - which the regional council passed 87-41 in February - authorising construction of big solar parks that can produce 10 gigawatt-hours of electricity per year.
The federal energy department estimates that about 40 to 50 proposals for large solar parks have been made across the country.
Will solar projects still go ahead in Valais?
The rejection doesn't torpedo solar parks entirely if the private sector wants to develop them.
But the 'no' did set back the region, seen as one of the sunniest and most apt for solar parks in Switzerland, against others like central Bern Oberland or eastern Graubünden vying for generous federal funding for such projects. At stake is up to 60 per cent of financing for big solar parks.
It also means solar projects will face a longer approval process in the canton.
Overall, Swiss federal authorities have set a target of 2 billion GWh in new solar energy under legislation promoting development of solar energy, adopted in September 2022. Some areas, like nature reserves, are excluded from possible development.
With concerns about climate change and their much-vaunted glaciers in mind, Swiss lawmakers have also already approved a plan that requires Switzerland to achieve “net-zero” emissions by 2050.
It also set aside more than 3 billion Swiss francs (about €3.14 billion) to help wean companies and homeowners off fossil fuels.