INVESTIGATION OF THE EFFECTS OF KOREAN POLICIES TO PROMOTE A GRID-CONNECTED MICROGRID

Microgrids have been considered a promising concept for integrating distributed energy resources (DERs) into the electricity grid. As such, to promote DERs in a grid-connected microgrid, we first develop an optimization model for the economic scheduling of DER generation to minimize the operation cost, including the cost of buying power from the utility grid. Despite optimal scheduling, utility-scale generation is still cost-effective. To overcome this barrier, a financial subsidy or mandatory policies are necessary promotion policies. We thus develop a framework to evaluate how the promotion policies perform based on the optimization model. Based on a case study in South Korea, we show that subsidizing the use of energy storage is an effective subsidy policy, with an appropriate autonomy level imposed by the government. In conclusion, our study suggests that a subsidy policy should be carefully designed by considering the energy independence of the grid-connected microgrid, cost reduction by utilizing DERs, and load shedding effects.