Today’s and futures power grids are characterised by a high share of renewable energy sources. This leads to a massive fluctuating power injection, which needs to be balanced by battery energy storage. POWERTECH Industrial Corporations USA has developed a new innovative Battery Energy Storage System for low voltage (LV) and medium voltage (MV), that provides grid stabilization and increased power quality: Four-Quadrant Operation (Active and Reactive Power Control), Peak Shaving and Load Balancing, day to night shifting of renewable PV Energy, reliable PV Power Supply by rolling clouds and provide control power to participate in this market. The further advantage of the POWERTECH' new battery energy storage is the ability to control harmonic emissions of power electronic equipment connected to the same busbar, by the use of active damping or active filtering functionality.