Germany – Accumulators, primary cells and primary batteries – Batteriespeicher BESS K13

The subject of the present project is the construction and operation of a grid-connected stand-alone battery energy storage system (BESS) with an electrical connection capacity of 8 MW and a usable storage capacity of 16 MWh on the customer's site. The storage system will be connected to the customer's own 5 kV medium-voltage grid via a medium-voltage transformer and will serve both the provision of system-relevant reserve energy and participation in arbitrage trading. The location of the battery storage system is on the power plant site of STADTWERKE FLENSBURG GMBH (SWFL). The system is to be implemented as a containerised or modular storage solution, consisting of battery systems, inverter units, transformer technology, protection and control technology, and the necessary ancillary systems. A key feature of the project is the permanent reservation of part of the storage capacity for the customer's operational requirements. In this regard, 3.5 MWh of the total capacity is to be continuously reserved as secured start-up energy for gas turbines. This energy reserve serves the reliable supply of critical start-up processes and ensures high operational availability of the generating plants, even in grid-critical situations or in the event of external supply failures. The remaining storage capacity is to be used for participation in energy trading. In particular, the marketing of flexibilities via short-term power markets is envisaged in order to generate revenues from price spreads and market-based arbitrage potential. In addition, the battery storage system is to be used to provide secondary control reserve (aFRR) and thus generate additional revenues from participation in the control energy market. By combining operational security reserve and market-oriented multiple use, an economically optimised mode of operation of the storage system is to be achieved.