A solar plant high above the fog line

Muttsee solar power plant

All photovoltaic systems rely on sunlight to work. But especially in winter time, sunlight can have a hard time penetrating the cloud cover in Switzerland. What better way to make full use of a solar plant than in an alpine terrain on 2,500 metres above sea level?

The energy service providers Axpo and IWB are building Switzerland's largest alpine solar plant by transforming the dam wall at Muttsee in the Canton of Glarus into a renewable power plant. From autumn 2021 the pioneer project AlpinSolar will produce 3.3 million kilowatt hours of electricity per year – half of it in winter. In other words, it will meet the electricity needs of 740 average four-person households.

Photovoltaic installations in alpine locations are particularly effective in winter thanks to the blue skies and reflective snow at high altitudes. The Muttsee dam wall is an ideal location for this pioneer project because it will rely exclusively on existing infrastructure and not require any additional land. In addition, the Muttsee dam faces the south, so has sun all day.

The Muttsee dam wall at 2500 m.a.s.l. will be equipped with 5,000 solar modules.

The Muttsee dam wall at 2500 m.a.s.l. will be equipped with 5,000 solar modules.

Meeting peak demand in winter

Swiss power plants struggle to keep up with the demand for energy in winter because people use more energy when it’s icy and cold. This makes Switzerland dependent on imported power in winter. As nuclear and coal-fired power plants are decommissioned in Switzerland and abroad, our dependence on imported energy is likely to grow.

The large-scale, alpine power plant AlpinSolar will generate 50 per cent of its electricity during the winter months and consequently support new renewable sources for this period of the year.

20-year commitment to solar

The Swiss discount supermarket chain Denner has agreed to purchase the solar power from Muttsee dam for the next 20 years. 

This commitment is of great importance, allowing the energy service providers Axpo and IWB to finance the high-altitude solar power plant with less financial risk.