UK-based Storelectric Ltd. is the winner of the NAM70 Challenge, a competition sponsored by Nederlandse Aardolie Maatschappij (NAM). The challenge, held to commemorate the 70th anniversary of NAM, sought opportunities to use existing oil and gas infrastructure for the large-scale storage of renewable energy.
Storelectric will receive €50,000 will now partner with NAM, jointly owned by Shell and Exxon, to implement its energy storage technology using compressed air in underground salt caverns. Plans call for building underground storage sites in the Netherlands and potentially the North Sea, to store energy from offshore wind farms and onshore solar power plants.
Excess electricity from intermittent renewable energy sources can be used to compress and store ambient air under pressure in an underground cavern. When electricity is needed, the pressurized air can be heated and expanded in a turbine to generate electricity.
However, air heats up as it is being compressed, and this heat must be removed before it can be safely stored; otherwise, salt caverns will melt. The remedy developed by Storelectric is to remove heat from the air during the compression stage and to use it to reheat air during the expansion stage.