CMP substations like this one in Norway sometimes need upgrades to accommodate new solar projects. If inflated prices prevent private companies from paying for these upgrades now, the cost may fall to ratepayers later. Credit: Courtesy of CMP / Spectrum News

Maine’s high court ruled Tuesday that a referendum blocking the controversial $1 billion hydropower corridor by an affiliate of Central Maine Power Co. running from the Canadian border through western Maine was unconstitutional.

In a 39-page ruling, five members of Maine’s Supreme Judicial Court said the portion of the November 2021 referendum that retroactively applied to the corridor project, which had previously secured a number of approvals, was unconstitutional.

Read the decision below.