Isle au Haut, Maine, received $211,000 from the US Department of Agriculture to help pay for a 311-kW solar power array that will be part of an island microgrid.
The island’s 140 electricity customers receive power from a 7-mile undersea cable that was installed in the early 1980s and has outlived its expected life.
In a sign of the challenges Isle au Haut Electric Power, a cooperative utility, aims to avoid by developing a $1.9 million microgrid, the island lost power for 31 hours in March because of storms leading to the use of an on-island 170 kWh backup diesel generator, according to the utility.
The solar facility will provide all the island’s electricity at an estimated annual cost savings of about $88,000, Sens. Angus King (I) and Susan Collins (R) said Sept. 4 after the grant was awarded by the USDA’s Rural Energy for America Program.
Isle au Haut residents pay about $0.32/kWh, as well as a $16 monthly meter fee, according to the senators.
The microgrid project includes a 1 MWh super capacitor storage system supplied by New York-based Kilowatt Labs.
Dynamic Grid, formerly Introspective Systems, based in Portland, Maine, and Brightmerge, an Israeli company, are providing the microgrid’s “transactive energy” platform. The system uses distribution level real-time prices signals to balance distributed energy resources by applying real-time control of heat pumps and energy storage, according to Dynamic Grid.
Isle au Haut Electric Power expects the storage equipment will cost $630,000 and the solar array will cost $539,000. The entire project, including federal investment tax credits, will cost $1.5 million compared with $2 million for installing a new undersea cable.
Besides the just-awarded USDA grant, the Isle au Haut utility is seeking a nearly $1 million loan from the department’s Rural Utilities Service. It also expects a $700,000 contribution by SunRaise, a tax equity investor.
As part of the microgrid, the utility is installing heat pumps in public buildings to use excess energy produced by the planned solar array. The heat pumps, which will be offered to residents, are expected to produce about $241,000 in heating savings, according to Isle au Haut Electric Power.
Despite some delays caused by the novel coronavirus pandemic, the utility plans to start installing the solar array this fall.
Isle au Haut isn’t the only Maine island considering microgrids and distributed renewable energy. A non-profit group is exploring creating a microgrid on Mount Desert Island while a request for proposals is underway for a battery and solar project on Matinicus.
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