Optimal design and economic evaluation of a battery energy storage system for the maximization of the energy generated by wind farms in isolated electric grids

In this paper, a methodology for the optimal sizing of a Battery Energy Storage System (BESS) targeting to supply a predefined and constant (guaranteed) amount of power to an isolated electric grid during the peak load-demand hours is presented. The BESS battery bank is charged using that part of the energy produced by wind parks interconnected with the power system, which is rejected by the electric network due to grid stability limitations. Thus, using the proposed BESS configuration results in increment of the wind energy penetration in the isolated power system and reduction of the air pollution caused by the thermal power stations. The economic viability of the optimally sized BESS configuration is investigated by calculating the investment discounted payback period and internal rate of return. The proposed method has been applied for the optimal design of a BESS supporting the isolated electric network of a remote island with significant wind potential. According to the economic analysis results, the installation of the proposed BESS is economically beneficial for both the BESS investor and the local electric network operator.