A method of storing electricity in large quantities using compressed air has received backing from RWE, General Electric, Zueblin and the German Aerospace Centre (DLR).
The ADELE (adiabatic compressed-air energy storage for electricity supply) concept involves compressing air during periods when electricity supply exceeds demand.
The resulting heat is then buffered in a thermal-energy storage unit and air is pressed into underground caverns.
When electricity demand increases later on, this compressed air can theoretically be used to generate power in a turbine by simultaneously recovering the heat.
RWE, General Electric and DLR signed an agreement in Berlin, Germany, on 19 January to jointly develop the technology.
The aim is to install an initial demonstration plant, which will start operations in 2013. It will have a storage capacity of one billion watt-hours (GWh) and will generate electrical power of up to 200MW.
It is hoped this will allow the concept to give backup capacity within a short time and replace 40 wind turbines for five hours during periods of intermittency.
The project will require advanced turbo machines and high-temperature thermal-energy storage
While the German Federal Ministry of Economics has offered state funding, the project members will contribute an amount of €10m (£8.7m).
The project will require advanced turbo machines and high-temperature thermal-energy storage to implement. The development of the latter is being led by Zueblin and DLR.
Some of the suitable locations being discussed for compressed-air storage power plants include regions with adequate geological salt structures, which can then be used to build underground caverns for the absorption of large quantities of compressed air. The companies also note that such salt structures should be close to wind turbines.