The Influence of Thermochemical Energy Storages with CaO/Ca(OH)2 on Future Industrial Energy Systems with High Temperature Steam Demand

As an important part of the energy transition, applicable energy storages for adapting energy demands to the volatile renewable energy production are a current subject of research. However, industrial energy systems, that are responsible for more than 25 % of the yearly energy consumption in Germany, have specific requirements on storages due to their high temperature process steam demand. Therefore, the integration of a thermochemical energy storage with CaO/Ca(OH)2, that is charged by electricity, and discharges steam with up to 50 bar and 480 °C is investigated. An existing German industrial power plant together with the thermochemical energy storage was modelled with a mixed integer linear programming approach. To evaluate the influence of the storage system in the future, hourly energy market price scenarios from 2025 to 2050 were used. The yearly economic and ecologic benefits of different storage sizes and the influence of the storage system on the industrial power plant are presented. All storage sizes were evaluated as economical viable with a positive net present value. The storage operation results in a strong reduction in gas and CO2 emissions; the second particularly in the years 2025 to 2035. Although, especially larger storage systems have stronger financial advantages with an investment starting in 2035. As a result, a modular based storage system with successive storage installations is recommended.