Axpo and IWB's 4,872-panel Swiss dam solar plant produced 3.8x more winter energy

Axpo and IWB installed 4,872 solar panels on the Muttsee dam in Switzerland at 2,500 meters. In its first winter the plant yielded 616 kWh per installed kW, 3.8 times more than lowland reference plants, with annual output of 1,434 kWh per kW. Since 2025 it has taken part in Swissgrid's PV4Balancing pilot.

• Winter yield reached 616 kWh per kW, 3.8x the Payerne reference plant
• Annual yield was 1,434 kWh per kW, about 3.3 GWh per year
• Panels are tilted at 51-65 degrees so snow slides off instead of accumulating
• The plant joined Swissgrid's PV4Balancing pilot in August 2025