Cuttyhunk Island, MA


Cuttyhunk Island is the westernmost of the Elizabeth Islands chain that lies between Martha’s Vineyard and the south coast of Massachusetts. The Town of Gosnold, named for the British explorer Bartholomew Gosnold who landed there in 1602, encompasses the entire island chain.

With a modest year-round population, Cuttyhunk could never justify an undersea utility cable from the mainland and has depended on diesel generators to supply its electric grid. The island hosts many summer visitors including boaters who favor the sheltered harbor and seek shore power during their stay. As a result of the island’s popularity increasing, so have the the operation and maintenance costs for the diesel power plant. With solar and battery storage prices falling and diesel prices rising, the island decided to go solar.

Solar Design Associates was retained to help power the island with a solar-plus-storage and generator hybrid micro-grid. SDA developed a black-start-capable system to include 350kWp of PV and 1.25MWh of storage capacity to provide the primary source of power for the island, satisfying the majority of annual requirements. The system runs in parallel with the existing gen-sets during periods f low sun. When solar and storage are unavailable, the generators automatically pick up the load. SDA served as Engineer-of-Record, providing design and engineering, procurement assistance, permitting support, construction management, and full system commissioning.