Siemens Gamesa Renewable Energy (SGRE) has begun operation of its electric thermal energy storage system (ETES). The storage technology makes it possible to store large quantities of energy and thus decouple electricity generation and use.The heat storage facility contains 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 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.
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 its 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. By using standard components, it is possible to convert decommissioned conventional power plants into green storage facilities (second-life option).
The Institute for Engineering Thermodynamics at Hamburg University of Technology and the local utility company Hamburg Energie are partners in the project. TU Hamburg carries out research into the thermodynamic fundamentals of the technology used. Hamburg Energie is responsible for marketing the stored energy on the electricity market.