Upgrades to transmission lines and substations could soon let more electricity from northern Maine wind farms make it to southern New England, bypassing congestion around Seabrook Station.
ISO-NE, the regional grid manager, has selected the Transmission Initiative Down East (TIDE) system proposed by Eversource and Avangrid as its preferred way to get more electricity flowing south. They say the project, which involves upgrades to 345-kilovolt transmission lines in the New Hampshire Seacoast and southern Maine as well as upgrades to substations in Massachusetts, New Hampshire and Maine, would help 1,200 megawatts of onshore wind generation planned for northern Maine to get integrated into the regional grid.
The proposals will still need state and federal regulatory approval, which undoubtedly will include much debate about how much of the cost should be born by ratepayers rather than investors. Eversource says construction could start by 2029 and will take several years.
