Siemens is to deliver a Siestorage energy storage system to Süwag Energie for grid stabilization and temporary storage of the volatile power fed into the distribution grid from wind and solar plants. The custom-made storage system is based on lithium-ion batteries and has a capacity of 135 kilowatt hours (kWh) in this version. Süwag Energie AG will use the storage system in conjunction with other distributed storage systems as part of the “green2store” research project. The storage system is to be installed in the low voltage distribution grid in the district of Flein, south of Heilbronn.
Süwag Energie will use the Siestorage system with three battery cabinets
For the Süwag Energie order, Siemens will first connect three battery cabinets made by South Korean battery manufacturer LG Chem in parallel and then connect them to the 4Q-IGBT converter specially optimized for energy storage applications on the DC side. Parallel connection of additional battery cabinets is already planned. The suitable C-rate for every application can be implemented in a range from c>0.5 to c<3 with the Siestorage modular energy storage system based on lithium ion batteries. The C-rate describes the quotient of current divided by capacitance and hence the maximum current of the battery in relation to its capacitance. This gives the reciprocal of the time for which a lithium-ion battery of the stated capacitance can be discharged at the maximum discharge current.