Throughout the summer, the microgrid system, developed earlier this year by Solar Design Associates Inc. of Harvard, Mass., has provided the majority of the electricity for Cuttyhunk residents as well as summer boaters visiting its harbor. The combination of solar and storage provides more than 80 percent of off-season electricity as the summertime population of 300 shrinks to about 50 year-rounders.
The island, which has 174 electric meters, had previously relied solely on diesel-powered generation with fuel delivered by barge for all of its electricity. The new Cuttyhunk microgrid comprises 1,020 solar panels with maximum output of 351.9 kilowatts, plus 1,000 kilowatt-hours of electric storage in a bank of lithium-ion batteries. The project was supported by a U.S. Agriculture Department rural electrification grant.
SDA is currently developing a solar-plus-storage system for the Isle au Haut Electric Power Co. in Maine that is projected to provide 100% of its year-round electricity and eliminate its dependence on a 35-year-old undersea electric cable. Isle au Haut has 140 year-round and seasonal electric customers.
On Cuttyhunk, Solar Design Associates served as Engineer-of-Record for the project, providing design and engineering, procurement assistance, permitting support, construction management, and full system commissioning.
Cuttyhunk, 14 miles by sea from New Bedford, is the westernmost of the Elizabeth Islands that comprise the town of Gosnold, whose 75 inhabitants counted by the 2010 Census make it the least-populated town in Massachusetts. Gosnold is named for 17thcentury explorer Bartholomew Gosnold, whose crew set up a sassafras-harvesting outpost on Cuttyhunk in 1602 and the first known English trading post in New England.