Optimal sizing of PV-battery for loss reduction and intermittency mitigation

Over these years, dependency of electric generation on renewables is increasing steadily. The renewable energy sources are usually connected to the electric grid on the distribution networks. Energy supply from prominent renewable sources like wind and solar are restricted due to the high level of unpredictability and intermittency associated with them. This leads to the inefficient and less reliable output from these sources. Thus proper generation prediction, sizing and intermittency mitigation of renewable energy sources such as wind and solar photovoltaic (PV) is necessary while placing them on the feeder. As these sources are distributed energy sources, the loss minimization can be one of the opportunities in addition to their generation support. This paper deals with the optimal sizing of solar PV and battery combination in a grid connected system. Solar PV generation is seen as the future generation source and battery storage with its matured technology can support it to become more reliable source in a power system. Here an analytical method for sizing of solar PV and battery is proposed. The line losses and intermittency minimization is the prime consideration for the sizing and placement of the solar PV and battery. To tackle with the variability of the solar PV generation, it is predicted by probability density function and supported by battery energy storage. The battery energy storage is properly sized to satisfy the state of charge limitations. The location and sizing methodology is applied to a 13-bus test system using MATLAB. With the proposed optimal sizing methodology the losses can be reduced up to 83 % during the solar PV generation period and a small amount of battery support can help to get constant power supply to the grid from the solar PV.