About Isle au Haut Electric Power Company

Before 1969, homes on Isle au Haut relied on individual generators. A community effort led by Patrick Tully built a powerhouse and about one mile of distribution line, forming the cooperative electric power company that still serves the island today. That one mile was eventually augmented to connect the community at Head Harbor and the entire east side of the island.

In 1983, the co-op installed a roughly seven-mile undersea cable from Stonington to Isle au Haut, laid along the ocean floor by a team led by Parker Waite. The cable replaced aging WWII-era generators as the island's primary power source. Though expected to last 15–20 years, it has substantially exceeded that, operating for more than four decades.

We maintain a diesel generator large enough to power the entire island when the mainland grid goes down. This gives our members greater service continuity than is typical on the mainland and reduces the need for private backup systems. In July 2026, the generator failed during an unusual mid-summer storm that took down our mainland feeder, causing our first 24-hour outage in a decade. In September, we installed replacement control electronics to prepare for winter. However, support for the generator’s 30-year-old electronics has been discontinued.

Since the cable project is now complete, we applied for a DoE grant to design a new automated microgrid with solar and batteries. Should we win the competitive process we will spend 2027 designing a system which will automate the switchover to island power during the mainland outages that occur up to 15 times a year. That system will likely replace the existing generator.

The co-op has also benefited from mutual aid across the broader cooperative network. Neighboring co-ops on Swan's Island and Fox Islands donated surplus transformers to help address a transformer shortage. When transitioning to smart meters, Cherokee Electric Cooperative in Alabama donated 300 brand new meters, allowing IAHPoCo to upgrade its metering infrastructure. These acts of generosity reflect the spirit of cooperation that defines rural electric cooperatives.