The newly-opened electrothermal pilot plant in Hamburg-Altenwerder, a world first, can store 130 MWh of energy for up to one week, and is aiming for a storage capacity in the gigawatt hour range.
The heat storage system uses around 1,000 tonnes of volcanic rock as an energy storage medium. It is fed with electrical energy converted into hot air by means of a resistance heater and a blower that heats the rock to 750°C. When demand peaks, ETES uses a steam turbine for the re-electrification of the stored energy. The ETES pilot plant is built by the Institute for Engineering Thermodynamics at Hamburg University of Technology and the local utility company Hamburg Energie and the capacity of the system remains constant throughout the charging cycles.
The aim of the pilot plant is to deliver system evidence of the storage on the grid and to test the heat storage extensively. In a next step, Siemens Gamesa plans to use the electrothermal storage technology in commercial projects and scale up the storage capacity and power. The goal is to store energy in the range of several gigawatt hours (GWh) in the near future. One gigawatt hour is the equivalent to the daily electricity consumption of around 50,000 households.
“Decoupling generation and consumption of fluctuating renewable energy via storage is an essential contribution to implementing the energy system transformation. We therefore need cost-effective, efficient and scalable energy storage systems,” said Andreas Feicht, State Secretary at the Federal Ministry of Economics and Energy.
“With the commissioning of our ETES pilot plant, we have reached an important milestone on the way to introducing high-performance energy storage systems. Our technology makes it possible to store electricity for many thousands of households at low cost. We are thus presenting an elementary building block for the further expansion of renewable energy and the success of the energy transition,” said Markus Tacke, CEO of Siemens Gamesa Renewable Energy.
The technology reduces costs for larger storage capacities to a fraction of the usual level for battery storage. By using standard components, it is possible to convert decommissioned conventional power plants into green storage facilities as a second-life option. Hamburg Energie is responsible for marketing the stored energy on the electricity market, and is developing highly flexible digital control system platforms for virtual power plants. Connected to such an IT platform, ETES can optimally store renewable energy at maximum yield.