Dimensioning and grid integration of mega battery energy storage system for system load leveling

In countries without hydropower potential, Peak load and spinning reserve have to be entirely covered by thermal generation. The corresponding environmental and economic burden is increasing on and on. This paper discusses how using mega Battery Storage Energy System (BESS) for system load leveling can mitigate the problem, and to which extent. Limitations on peak shaving of load profiles with flat and long peak are identified and quantified. It proposes a simple empiric method for dimensioning the capacity of mega BESS connected to primary substations (S/S) with loads. The method is based on detailed load following operation calculations performed for the United Arab Emirates. The concepts of S/S peak inversion and reduced S/S firm capacity are introduced. Finally, simplified scheme for grid integration of mega BESS to S/S without loads is proposed.