Swiss energy firm Axpo has built a snaking wall of solar panels on Switzerland's longest dam to maximize green energy generation throughout the winter months.
The Lake Muttsee dam in the central Swiss canton of Glarus is almost 2,400 meters above sea level and surrounded by snow-capped peaks, which Axpo’s AlpinSolar project team describes as a crucial benefit.
"One of the qualities of alpine solar plants is that especially in winter they produce up to three times more electricity than a comparable facility in the midlands," said Jeanette Schranz, communications lead for renewables at Axpo.
The dam's about 5000 solar panels generate 3.3 million kilowatt hours of energy per year, enough to power around 700 houses. The panels were installed last year, and production at the site has already started.
According to Schranz, Switzerland's mountains are less affected by fog during the colder months, therefore the panels receive more sunlight than they would at lower altitudes.
"The reflection from the snow also helps," Schranz said, "and solar panels prefer the cold and have a higher yield in cooler temperatures."
The AlpinSolar project is part of Axpo’s wider plan to deploy 4,200 solar installations in the alpine country's mountains and low-lying regions by 2030.
The Swiss government is also making it easier for solar energy to become more widely used. The federal parliament amended the country's Energy Act last year to expedite the approval process for new solar projects that aim to provide considerable amounts of energy during the winter months.
The country's push for more green energy sources is linked to its intention to phase out nuclear power. The parliament resolved in June 2011 not to replace any existing reactors, which was confirmed in a 2017 referendum.
Schranz says a balanced power mix is critical to Switzerland's transition to green energy. “Alpine solar plants can also make an important contribution here,” she said.