GE has won a contract to supply the turbines for a novel pilot project combining wind energy with a hydro pumped storage plant. GE's 3.4MW turbines will be the tallest installed and part of a world-first pump storage solution
The Gaildorf project, located in Germany’s Swabian-Franconian forest on the Limburger Berge uplands, will comprise four of GE’s new 3.4-137 turbines and a 16MW pumped storage hydro-electric power plant supplied under a separate agreement between Max Bögl, Naturspeicher and Voith.
The base of each wind turbine is to be used as a water reservoir, increasing tower height by 40 metres and extending tip height to a record-breaking 246.5 metres, GE said. The lower reservoir for the pumped storage plant lies in a nearby valley, 200 metres below the wind turbines.
The combined wind and hydro power plant will be able to provide balancing power for fast-response stabilisation of the grid, said GE. This would be an additional source of earnings on top of normal participation in the wholesale electricity market.
The wind turbines and the pumped storage unit will both sell electricity into the wholesale market with their combined operation optimised to make the most of price fluctuations.
During times of peak demand and high electricity prices, the hydro plant will be in production mode. When demand and prices are low, the hydro plant will be in pump mode, pumping and storing water in the upper reservoir for later use.
The net effect will be to use the stored hydro capacity to balance the intermittent nature of wind power through the optimal use of energy at different times of the day, GE said.
The turbines are scheduled to be commissioned by the end of 2017 and the full Gaildorf power plant is expected to be operational by the end of 2018.
Whether the pilot project will be commercially viable remains to be seen. German pumped storage plants are struggling to operate profitably and prices in the balancing market are falling as more players enter the market.