RWE and GE are to jointly develop and validate an advanced energy storage technology in a bid to combat the challenges posed by rising levels of wind energy generation on the grid.

The two companies have signed a memorandum of understanding (MoU) to investigate the feasibility of advanced adiabatic compressed air energy storage (AA-CAES) and develop a demonstration plant by 2012.

The MoU is aimed at finding alternative paths for large-scale energy storage in an effort to better align distribution of supply and demand currently within the electricity market, says RWE. While AA-CAES technology has higher efficiencies than currently-available alternatives, the companies face major challenges.

“The highly fluctuating power input is expected to increase in the future, if only because of the planned massive expansion of wind energy. Therefore it is important to address this challenge and develop concepts for efficient storage in due time,” said Dr. Johannes Lambertz, CEO of RWE Power AG, Fossil-Fired Power Plants portfolio.

A major challenge will be to develop a compressor technology that can withstand high temperatures during compression and ensure high availability. To prevent this heat from being lost, it is extracted from the compressed air before the latter is stored in a cavern, and directed to a separate thermal energy storage.

“We’re excited about this project because we believe that thanks to GE’s vast experience in compressor technology, we have the capability to study and propose unique solutions as an alternative to the current state of art,” said Claudi Santiago, president and CEO of GE’s Oil & Gas, which will study the compressor technology required.

The most interesting sites for CAES power plants are regions where caverns of worked-out salt mines are present.