According to a representative from sodium-ion (Na-ion) battery energy storage system (BESS) startup Peak Energy, the company will pilot a 3.1MWh system at Energy firm RWE’s Eastern Wisconsin, US lab.

Energy firm RWE added 2GW to its US operating capacity in 2025, bringing its total operational capacity to nearly 13GW across the country.

A busy week of grid-scale BESS project news from Germany, with numerous development, project, optimisation and tolling partnerships announced.

Power firm RWE is about to start building a 400MW/800MWh BESS project in Germany, among the largest in the country to reach the construction stage. In related news, Kyon Energy has connected a 282MWh project to the grid, possibly the largest in the country to reach that milestone.

RWE Clean Energy has commissioned the Stoneridge Solar PV project in Texas, adding 200MW of solar PV and 100MW/200MWh BESS to its operational portfolio.

PJM has awarded 23 battery energy storage system (BESS) resources, totalling 2.2GW, with interconnection agreements (IAs) in its first transition cycle (TC1) of the reformed interconnection process.

European BESS news from project owners Premier Energy Group, Verbund, Eco Stor, Ingrid Capacity, Ric Energy, Ganfeng Lithium, EP Group, RWE and Giga Storage, securing acquisitions, financings and route-to-market (RTM) deals for multiple gigawatts of capacity this past week.

Power firm RWE has launched construction on a 400MW/700MWh BESS project in Bavaria, Germany, the largest being built in the country.

San Diego Gas & Electric (SDG&E) is seeking regulatory approval to acquire an operational portion of a BESS facility located in Imperial County, California, from the US development arm of German multinational energy company RWE. 

Power generation firm RWE has put a BESS in the Netherlands into commercial operation, its first that is capable of providing inertia to the grid.