PNNL

Abstract

This report examines the economic and resilience benefits of a proposed microgrid in Northampton, Massachusetts that would link the Northampton Department of Public Works, Cooley Dickenson Hospital (CDH), and Smith Vocational Area High School (SVAHS). Microgrid assets include diesel generators, solar photovoltaics (PV), energy storage, and an onsite biomass facility. We modeled financial benefits of microgrid operation—including demand response revenue, capacity charge reduction, demand charge reduction, outage mitigation, energy charge reductions due to solar PV energy production, and renewable energy credits—by simulating one-year of microgrid operations in the Battery Storage Evaluation Tool. Over a 20-year life, a 441 kw / 441 kWh battery energy storage system and 386 kW solar array are estimated to generate $2.5 million in present value benefits, yielding a 1.16 return on investment ratio. To evaluate system resiliency, we randomly generated a large number of outages for scenarios characterized by changes in outage duration, season, system configuration, and distributed generator availability. Results of this study demonstrate that forming a microgrid results in the highest resiliency level for all microgrid partners when experiencing short-duration outages of one week or less. Compared with 3-day and 7-day outages, survival rates drop significantly for prolonged outages (14 days) due to fuel shortages. CDH can improve survivability during long-duration outages by limiting load sharing and therefore conserving fuel.