Optimal Sizing of Energy Storage Systems Considering Their Economical Operations in a Microgrid

Energy storage systems (ESSs), including battery energy storage systems and hydrogen energy storage systems, are critical components of microgrids in efficiently managing electric power supply and demand. On the other hand, the ESSs raise concern regarding design and operation of the microgrids due to their expensive installation costs. This paper introduces a problem framework and its solution method for calculating the optimal sizes of multiple ESSs in a microgrid. The authors’ proposal makes it possible to obtain the ESS sizes that realize economical operation of the microgrid after the ESS installation. The problem discussed in this paper is originally formulated as a bilevel optimization problem, but it is reformulated as an operation scheduling problem based on the Karush-Kuhn-Tucker approach. Consequently, the techniques developed to solve operation scheduling problems become applicable.