Integrated design of Battery Energy Storage System with PV for university campus energy sustainability

This document presents a real case study evaluating the optimal design for installation of a battery energy storage system (BESS) together with a photovoltaic system (PV). The selected case study was the UNIFEI campus in Itajubá-MG, Brazil, supplied by the Brazilian distribution utility CEMIG. The tariff structure in Brazil is essentially classified in two groups: group A for customers supplied in medium, high voltages, and underground systems and group B, supplied in low voltage systems. UNIFEI is supplied at 13.8 kV medium voltage level, thus classified as group A4, and with the time of use (TOU) tariff “Green Tariff”, i.e. with different energy prices for peak and off-peak periods and a single price value for power demand. Therefore, based on the campus energy bills, it was developed and applied an approach using the software HOMER® - Hybrid Optimization of Multiple Energy Resources to calculate the demand power and energy size for the battery energy storage system(s) using ferrous lithium batteries mainly focusing in saving electricity generated by the PV systems during the day to supply electrical energy during peak hours at night, thus avoiding high electricity prices from the utility. Then, it was evaluated the possible technical and economic impacts. This paper contributes to the global issue on sustainable development, taking universities as living labs in energy transition.