Axpo plans first large-scale alpine solar plant in Switzerland

Axpo also wants to use the Limmern pumped storage plant to produce solar power. As the Baden-based energy company writes, it is planning a solar plant with 6000 photovoltaic modules and an area of 10,000 square meters on the Muttsee dam. The plant is to have an installed capacity of 2 megawatts and generate 2.7 gigawatt hours of electricity per year.

The "PV Muttsee" project envisages a plant with an installed capacity of 2 megawatts and an annual electricity production of 2.7 gigawatt hours. A good 6,000 PV modules are to be installed on an area of 10,000 square meters. Axpo will submit the corresponding building application in the next few days. "The Muttsee dam is exceptionally well suited for photovoltaics," says Christoph Sutter, head of new energies at Axpo. "We have an existing infrastructure that has a grid connection and faces south and is therefore optimally exposed to the sun. In addition, the plant is located at an altitude of almost 2,500 meters and thus provides a lot of electricity, especially during the winter months."

Photovoltaic plants in the alpine region deliver - unlike plants in the lowlands - about half of their electricity production in the winter half-year. There are several reasons for this: At high altitudes, there is less fog and correspondingly more solar radiation. In addition, the efficiency of PV modules is higher at low temperatures. And finally, the sunlight is reflected by the snow cover, which leads to a higher solar power yield in winter.

The solar project at the Muttsee dam is unique and trend-setting in Switzerland. Axpo will therefore apply to the SFOE to include the plant in the list of lighthouse projects.
In addition, Axpo is currently in discussions with potential partners interested in purchasing a portion of the solar power produced at Muttsee under long-term contracts.

Lack of winter power: Alpine PV as part of the solution

Switzerland consumes significantly more electricity in winter than it produces. This winter electricity problem will intensify in the coming years when existing large power plants in Switzerland and abroad are taken off the grid. During the last few years, renewable production capacity in Switzerland has been expanded, especially in photovoltaics on the Central Plateau (between 2013 and 2017, photovoltaics accounted for almost 90 percent of the expansion). However, this expansion does not alleviate the winter electricity problem. This is because photovoltaic plants on the Central Plateau deliver only a quarter of their electricity production during the winter months.

The plant is intended to contribute to electricity production, especially in winter, when Switzerland often consumes more electricity than it produces itself. It is located at an altitude of 2500 meters, well above the fog line. In addition, the reflection of sunlight by the snow increases the yield. According to Andy Heinz, head of production and grids at Axpo, more sites should therefore be expanded that are not located in protected areas and are already well developed. "However, the political and economic framework conditions must also be right for this."