Optimal Battery Capacity for Residential Rooftop PVs With Consideration of Net-Metering Scheme Compensation Period

Abstract

With the significant increase of the prosumers in the world, the battery energy storage system (BESS) has become an important device to enhance the performance of renewable energy generation. By focusing on residential scale of rooftop PVs, BESS has been developed and applied in many aspects especially in terms of electricity charge saving. Many papers propose the methodology to control the operation of BESS, while many papers propose the methodology to determine the battery capacity. As f or this paper, the proposed methodology will simultaneously determine the operation schedule and battery capacity of BESS for rooftop PVs under a net-metering scheme (NMS). The main objective is to maximize the net present value (NPV) of the prosumers. The battery capacity will be constrained by the period of the NMS compensation which will be effective for only one year of each electricity bill. The numerical results show that , for the TOU structure without demand charge, an appropriate BESS should have C NOM,DC as high as possible to increase the revenue from BESS and have P NOM,DC as low as possible to reduce the total investment cost (TTC). Also, by considering the limit period of the NMS compensation, an appropriate battery capacity should not be higher than monthly residential load consumption. Lastly, the sensitivity of electricity tariff shows that the NPV will increase proportionally by the increment of electricity price, which will reduce the break-even year of the investment.