Siemens unveils storage in rocks

Siemens and two partners are developing a thermal storage system for wind energy that involves a rock-filled insulated container.

They are operating a test set-up at Hamburg-Bergedorf for the so-called Future Energy Solution (FES).

FES converts excess wind energy into heat in rock fill, where it is stored and protected with an insulated cover. A steam turbine can convert the heat energy back to power whenever needed.

The simple principle of this store promises an extremely low-cost set-up, according to Siemens.

The company is working on the project alongside Technical University Hamburg Harburg and urban utility Hamburg Energie.

They are establishing a complete thermal store on an aluminum smelter site in Hamburg-Altenwerder.

The full-size system will be able to store about 36MWh of energy in a container with approximately 2000 cubic metres of rock.

“The technology of our FES store deliberately uses mainly tried and trusted technology,” Siemens project manager Till Barmeier said.

“Because we are working here with tested thermal components and a series-ready steam turbine, we will be able to offer a practical solution within a few years,” he said. “Our complete experimental system will be operational in just around 15 months.”

Image: generic steam turbine (Siemens)