Energy generation without leakage in the Swiss Alps: Story in the 2/2022 Issue of the German Trade Magazine 'KE-NEXT'

32 ke NEXT · 02 2022 The Muttsee lake is the main reservoir of the pumped storage plant with a capaci- ty of 23 million cu- bic metres of water. Image: Axpo Power Tube forming Energy generation without leakage in the Swiss Alps Only two years after commissioning, leaks were detected on hydraulic stainless steel tubes at one of Europe’s largest pumped storage plants in the Swiss Alps. In some areas, conventional stainless steel cutting ring fittings had been unable to withstand the strong vibrations at exposed locations of the power plant. Kraftwerke Linth-Limmern AG now relies on the tube forming system from STAUFF. T he principle is simple: The main task of a pum- ped storage plant is to store energy. When there is excess energy in the power grid, for example during the night, water is pumped from a lower reservoir to a storage reservoir at a much higher altitude. The water acts as a storage medium and in a way takes on the role of a battery: When energy is needed, for example during periods of peak demand during the day, the water is drained and drives turbines. Electricity can be genera- ted and fed into the power grid within a matter of se- conds. This principle means that pumped storage plants are often referred to as “trump cards” for the energy revo- lution. While power generation through wind power and photovoltaic systems fluctuates and cannot be controlled, hydropower in a pumped storage plant can be accessed flexibly and at short notice. The challenge of compensating for phases of low power generation from sustainable sources or periods of peak demand can be overcome by integrating pumped storage plants – without having to resort to nuclear power or fossil fuels. The Limmern pumped storage plant is located in the Swiss Alps, around 100 km from Zurich. During the la- test expansion stage, the Muttsee lake 2474 m higher up was integrated in the power plant: The 1054 m long re- taining structure allows the lake to store 23 million cubic metres of water. The Limmernsee lake 630 m lower down acts as the lower reservoir. The water drained from the Muttsee lake can drive four turbines with a capacity of 250 MW each. In total, Kraftwerke Linth-Limmern have a capacity of 1520 MW after integration of the Muttsee lake. An exceptional pumped storage plant The Limmern pumped storage plant was commissioned in stages in 2016/17. Only two years later, leaks were detected on hydraulic lines during maintenance work. Uwe Bröllos is the Key Account Manager at Fluidtec AG in Kreuzlingen, the authorised STAUFF partner for Focus