Design of a Resilient and Eco-friendly Microgrid for a Commercial Building

Abstract

Recent natural disasters such as hurricanes Harvey and Maria have caused great disruption to the electric grid system.
 Additionally, government authorities have set ambitious goals to reduce greenhouse gas emissions. Thus, there is a growing interest in making the electric power systems more resilient while reducing their carbon footprint. In this work, a methodology to design a resilient and eco-friendly microgrid is presented. First, the input parameters of the model are defined; second, simulation of different
 microgrid configurations are performed in HOMER Grid software; third, the outputs of the model are analyzed; and finally, a microgrid configuration is selected based on economic, environmental, and resilience criteria. The considered microgrids consist of PV, battery, natural gas generator, and the electric load of an office building that consumes an average of 2 MWh per day. Different component sizes were used to determine the configuration with the lowest generator size to provide power during a two-day outage in the summer peak load. Environmental and economic analysis were performed to show the tradeoffs between different system design goals. The results indicate that installing a microgrid in an office building with a 600 kW PV array and 2.8 MWh lithium-ion battery can avoid the release of up to 287 tons of CO2 per year. The same microgrid configuration can endure a two-day blackout during the highest electric demand in the hurricane season without the need of a polluting backup generator. From this study, it was concluded that the optimal microgrid configuration depends on specific needs. Additionally, based on current technology costs, large PV systems with small batteries are economically more attractive than the base case configuration.