An Optimal Methodology for Sizing and Selection of Battery Energy Storage System in Standalone Solar PV Systems

Abstract

This paper presents a two-step cost-based method of optimally sizing and selecting BESS in standalone solar PV system applications considering predicted solar radiation data and economic performance (BESS cost analysis). The methodology is basically divided into two distinct parts; the first part is the sizing process and the second part is the selection process. In the first part, several BESS sizes suitable for a particular standalone PV system are determined using energy deficit and supply interruption outcomes of a PV system simulation with predicted hourly solar radiation series, hourly load demand and battery storage capacity as simulation parameters. In the second step, the economic performance of the determined BESS sizes is evaluated through a cost analysis process where two financial metrics; net present value (NPV) and payback period (PBP), are utilized. This step is necessary in order to ascertain the investment risks and benefits of the BESS sizes. To test its adequacy, the methodology was applied to two case studies; a residential load and a commercial load, and the results obtained for both case studies suggests that combining BESS sizing using predicted solar radiation data and BESS selection considering economic performance is an adequate process of incorporating BESS in standalone PV system applications.