General Electric Co., through its GE Renewable Energy business, says it has signed a turbine supply agreement with Max Bogl Wind AG to deliver and commission what it is calling the world’s tallest and first-ever wind turbine integrated with pumped storage hydro-electric power.

According to GE, the full scope of the Gaildorf project, located in Germany’s Swabian-Franconian Forest, on the Limpurger Berge uplands, will consist of four units of GE’s new 3.4-137 wind turbine technology and a 16 MW capacity pumped storage hydro-electric power plant, to be supplied under a separate agreement between Max Bogl, Naturspeicher and Voith.

The company notes that the base and surrounding area of each wind turbine tower will be used as a water reservoir, effectively increasing tower height by 40 meters. At a total tip height of 246.5 meters, these units will become the tallest wind turbines in the world to date.

GE states that the Gaildorf project marks a major step forward in balancing power demand and supply fluctuations using renewable energy sources: The combined wind and hydro power plant will provide balancing power for fast-response stabilization of the grid, maintaining a low cost of electricity for residents in Germany.

Further, GE states that its 3.4-137 wind turbine generators will sit at a hub height of 178 meters, while the lower 40 meters of each tower and its surrounding area will be utilized as active water reservoirs to store energy. A nearby valley, approximately 200 vertical meters below the wind turbines, will house an additional lake and a 16 MW capacity pump/generator hydro plant.

During times of peak demand and high electricity prices, the hydro plant will be in production mode. During times of low electricity demand and lower prices, the hydro plant will be in pump mode, pumping and storing water in the upper reservoir for later use.

GE’s 3.4-137 machine is part of its new 3 MW wind platform, unveiled late last year – a platform well-suited for a variety of wind conditions throughout Europe. The new units feature software and analytics capabilities that are compatible with GE’s Digital Wind Farm ecosystem, powered by the Predix software platform.

The four wind turbines are expected to be commissioned by the end of 2017, and the full Gaildorf power plant is expected to be operational by the end of 2018.