A ‘milestone’ electric thermal energy storage system operated by Siemens Gamesa Renewable Energy is now operational.
The heat storage facility is located in Hamburg-Altenwerder in Germany and contains around 1000 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, electric thermal energy storage (ETES) uses a steam turbine for the re-electrification of the stored energy. The ETES pilot plant can thus store up to 130 MWh of thermal energy for a week. In addition, the storage capacity of the system remains constant throughout the charging cycles.