E.ON Kraftwerke has awarded a contract to Voith for the modernisation of a generator at its 620MW Waldeck 2 pumped storage power plant in North Hesse, Germany.

Under the terms of the contract, which is worth approximately €9m, Voith will replace, assemble and commission the stator and rotor of machine 6 at the plant, increasing the efficiency by around 10%.

The contract also includes an option for the modernisation of an additional machine unit for around €5m.

The Waldeck 2 pumped-storage power station houses two generators, which have a capacity of 265MVA.

Voith, which delivered the original generators when the facility was constructed in 1970, said the vertical placement of the classical pump-turbine unit presents a challenge in the modernisation programme.

The turbine is situated vertically above the motor-generator and a multi-stage pump is equipped below.

Voith will have to first disassemble the original turbine to replace the generator.

Voith Hydro management board chairman Roland Münch said: “Pumped storage power plants such as Waldeck will continue to make a vital contribution to secure and stable energy supplies.

“As giant batteries, they store energy from irregularly available regenerative sources such as wind and solar and feed this energy quickly and flexibly back into the grid as and when required.

“Hydropower is reliable, sustainable and climate-friendly, and has long become an indispensable part of the

mix. This is why we are consistently developing our technologies for utilising these energy sources.”