Sizing battery energy storage for wind farms based on wind power forecast uncertainty in the bulk power system

Wind power brings additional unpredictable imbalances between load and generation, this paper proposes a novel methodology to optimize the battery-based energy storage(BESS) capacity for wind power forecast errors in the bulk power system. In the design of energy storage allocation capacity, in addition to considering the forecast errors of wind power, the proposed method also takes into account the load characteristics and the regulating ability of conventional units. Based on the scheduled appropriate wind power forecast errors compensated by BESS, the optimal energy state of BESS is designed, which enables BESS to compensate the errors optimally. Then, daily system operation is simulated in details over a year to obtain the system operation costs. The savings in operating costs of the system and investment cost of BESS are compared to determine the optimal capacity of BESS. The effectiveness of the optimal approach has been tested by numerical examples.