Developing a PV and Energy Storage Sizing Methodology for Off-Grid Transactive Microgrids

Abstract

A simulation tool was developed through MATLAB for comparing Centralized Energy Sharing (CES) and Interconnected Energy Sharing (IES) operating strategies with a standard Stand-Alone Photovoltaic System (SAPV). The tool can be used to investigate the effect of several variables on cost and trading behavior including: initial charge of Energy Storage System (ESS), amount of load variability, starting month, number of stand-alone systems, geographic location, and required reliability. It was found that the CES strategy improves initial cost by 7% to 10% compared to a standard SAPV in every simulation. The IES case consistently saved money compared to the baseline, just by a very small amount (less than 1%). The number of systems did not have a demonstrable effect, giving the same cost per system whether there were 2 systems or 50 involved in the trading strategies. Geographic locations studied (Indianapolis, Indiana; Phoenix, Arizona; Little Rock, Arkansas; and Erie, Pennsylvania) showed a large variation on the total installed cost with Phoenix being the least expensive and Erie being the most expensive location. Required reliability showed a consistent and predictable effect with cost going down as the requirement relaxed and more hours of outage were allowed.