Limmern pumped storage power plant: first electricity supplied to the Swiss grid ten years ago
At 9.57 a.m. sharp on 18 December 2015, the moment had arrived: the first of the PSWL's four turbines fed electricity into the Swiss transmission grid for the first time. Since then, it has produced a total of around 9.3 terawatt hours of electricity. That is roughly equivalent to the annual consumption of all Swiss households combined. To achieve this, the four pump turbines have turbined or pumped back up a total of 6.2 billion cubic metres of water. This is roughly equivalent to the volume of Lake Thun or the annual water consumption of all Swiss households for around 14 years.
Billions invested in security of supply
Axpo invested around CHF 2.1 billion in this once-in-a-century construction project in the Glarus Alps. With its two reservoirs, the PSWL functions like a giant battery for renewable energies. When there is a lot of electricity available from photovoltaic and wind power plants, the PSWL uses this surplus energy to pump water from Lake Limmern to the higher-lying Lake Mutt.
When demand exceeds production, the water flows back through the turbines into Limmernsee and the pumped storage plant generates electricity. The PSWL thus compensates for short-term fluctuations in production and demand, making an indispensable contribution to Switzerland's secure and reliable electricity supply.
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Axpo Holding AG
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