Siemens Gamesa has installed the world's largest electrothermal energy storage system in Germany, enabling thousands of homes to store electricity at a low cost. Siemens Gamesa has installed the world's largest electrothermal energy storage system in Germany, enabling thousands of homes to store electricity at a low cost. Siemens Gamesa Renewable Energy (SGRE), a German-Spanish partnership with wind turbine manufacturer, has embarked on a pilot project that it describes as a milestone in the development of energy storage solutions. The company announced the launch of its electric thermal energy storage system (ETES). The high-performance pilot plant developed by the company together with the Engineering Thermodynamics Institute at Hamburg University of Technology and the local utility Hamburg Energie was funded by the German Federal Ministry of Economy and Energy. The heat storage facility in Hamburg-Altenwerder, which consists of about 1000 tons of volcanic rock, is fed by electrical energy converted into hot air up to 750 ° C. At peak demand, ETES uses a steam turbine to reelectrify stored energy. The ETES pilot plant can store 130 MWh of thermal energy for a week. In addition, the storage capacity of the system remains constant throughout the charging cycles. Siemens Gamesa Renewable Energy plans to develop this pilot project to a few GW. 1 GW of electricity stored at the facility will be able to meet the one-day needs of 50,000 households.