Heyde, Michael von derMichael von derHeydeSchmitz, GerhardGerhardSchmitz2021-06-282021-06-282022-01-01Encyclopedia of Energy Storage (Elsevier): 108-121 (2022-01-01)http://hdl.handle.net/11420/9804An energy storage concept based on high-temperature thermal energy storage in a packed bed of crushed rock is presented. The packed bed is charged with hot air from an electric heater. At discharge, the stored heat is transferred with a heat recovery steam generator to a conventional water-steam cycle for electricity generation. A fan is used to move the air in closed loop. The deployment of the storage concept in existing large-scale water-steam cycle power plants is feasible, as the low-cost storage material is resistant to high temperatures. Further applications are industrial process heat electrification, waste heat recovery or combined heat and power generation. The power-to-power efficiency is mainly limited by the water-steam cycle, the fan work at discharge and the heat losses. Thermal destratification inside the packed bed limits the usable storage capacity with respect to the nominal storage capacity and must be compensated by packed bed over-sizing. The first demonstration plant with a thermal storage capacity of 130 MWhth and a storage temperature up to 750 °C has been commissioned in July 2019 in Hamburg, Germany.enCarnot batteryEnergy storagePacked bedPower to heatRock bedThermoclineTechnikBook Part10.1016/B978-0-12-819723-3.00053-6Other