Siemens is working on an energy storage solution, which is focused on using excess wind power in a novel way.
The excess energy would be stored as heat in ‘hot rocks’ before being converted back to electricity using a heat turbine.
The German government-backed project will see the energy being stored using an insulated cover. The system consists of a fan that uses an electrically-heated air flow to heat the stones to high temperatures, with the thermal energy then converted back to electricity when needed using a steam turbine.
Siemens say the only limit to the concept is the space required for the rock-filled insulated container.
The project, which has received research funding from the German Federal Ministry for Economic Affairs and Energy, is now operating a test system named Future Energy Solution (FES) at Hamburg-Bergedorf in Germany.
While the trial is currently only testing the thermal requirements for the storage process, Siemens said its researchers plan to test the complete energy conversion in spring of 2017 and are now establishing a large scale version of the technology on the Trimet aluminum smelter site in Hamburg-Altenwerder.
This full-size FES will be able to store around 36MWh of energy in a container holding around 2,000 cubic metres of rock and be capable of generating up to 1.5 MW of output for up to 24 hours a day, Siemens said.
Researchers working on the pilot expect it to generate effectiveness of around 25 per cent even in this early development phase, while the concept has the potential for an effectiveness of around 50 per cent, the firm added.
Till Barmeier, project manager at Siemens, said the complete experimental system will be operational in around 15 months.