Maine's rocky coast is home to thousands of islands -- 3,166 of which have been listed on the Maine Coastal Island Registry. Many of these islands are very small -- some mere ledges sticking up above the mean high tide mark -- while others sport communities of year-round residents. Island living offers a unique lifestyle, while posing challenges to residents: how do you get drinking water? What energy resources do you use for lighting and heating? What will it take to make living and doing business on the islands economically viable?
Uninhabited Duck Islands beyond a strip of the Cranberry Isles, Frenchman's Bay, Maine.
The answers to these questions depend on the wheres and whats of each island. Some islands are tied to other islands or the mainland through pipes, cables, and even bridges. Other islands are owned by one landowner, are undeveloped, or are more remote and pose different challenges. Some islands may have cost-effective ocean energy resources just beyond their shores, opening the door to a whole new realm of opportunity for islanders.
The Island Institute identifies fifteen year-round island communities off the Maine coast, sorted into three geographic regions. Five year-round communities lie within Casco Bay. Peaks, Great Diamond, and Cliff Islands are all part of the city of Portland. Long Island seceded from Portland in 1993 and now forms its own town. Great Chebeague was a part of the town of Cumberland until 2007, when it seceded and became the town of Chebeague Island. Of these, Peaks is the largest island with over 800 permanent residents, and a summer population that may rise as high as 6,000.
Six island communities fall within Penobscot Bay. Vinalhaven and North Haven are the largest, with over 1200 people on Vinalhaven and over 300 on North Haven. Many more people come for the summer. Isle au Haut is home to about 80 people, and is mostly part of Acadia National Park. Islesboro has over 600 residents, Monhegan about 75, and Matinicus about 50.
The remaining four communities lie farther downeast, clustered south of Mount Desert Island. Swan's Island has about 300 people; Great Cranberry about 40 year-rounders and about 300 summer residents; Islesford, or Little Cranberry, has more permanent residents despite its smaller size. Long Island (not the one in Casco Bay) is home to the village of Frenchboro.
Beyond this list, hundreds of other islands have structures on them where people live at least part of the year, and people do winter over on islands outside of these fifteen communities.
Some of these -- mostly the more populous islands closer to shore -- are connected to the mainland electric grid by underwater distribution cables. For example, Great Cranberry Island is connected to Manset on mainland-tied Mount Desert Island by an underwater line owned by Bangor Hydro. Waves during a winter storm in February 2009 caused the line to suffer an outage. Great Cranberry and neighboring Islesford lost power. In that case, the utility provided a temporary repair within hours, and installed temporary generation to cover the islands' load while a more permanent fix could be made.