Wind turbines line a ridge on Stetson Mountain on July 14, 2009, in Washington County. Credit: Robert F. Bukaty / AP

AUGUSTA, Maine — The basics and arguments surrounding a proposed transmission line that would run between Aroostook and Kennebec counties are fairly well-known by now.

But not all Mainers are up to speed on the two-part plan that would connect a massive new wind farm in northern Maine to the New England power grid, so here are answers to some questions about the Aroostook Renewable Gateway and King Pine Wind projects.

Which companies are behind the transmission line and wind farm?

LS Power, a New York-based energy firm that has projects across the U.S., is in charge of the proposed Aroostook Renewable Gateway transmission line. Longroad Energy, a Boston-based renewable energy firm with a portfolio that also spans the country, is leading the proposed King Pine Wind farm that will provide power to the line.

How big are the proposed transmission line and wind farm?

While final routes and specifics are undergoing reviews and potential revisions, LS Power has said the transmission line will extend for between 140 and 160 miles. It would stretch from a new substation at the southern end of Aroostook County in Glenwood Plantation to the existing Coopers Mills substation in Windsor, just outside of Augusta.

The King Pine project, according to Longroad Energy, will feature more than 170 wind turbines covering about 4,500 acres centered around Webbertown Township, west and northwest of Houlton. The farm would be the largest land-based wind project east of the Mississippi River.

The new infrastructure will allow Aroostook County and the wind farm to connect to the ISO New England power grid that operates in Maine and five other states. Supporters have said it will support rural renewable energy generation projects that have struggled due to lacking a connection to the broader New England grid.

How many homes could be powered by this new infrastructure?

The King Pine Wind farm is expected to produce about 3 billion kilowatt-hours per year, which is enough to power roughly 270,000 homes per year in Maine and 180,000 homes in Massachusetts, according to Longroad Energy.

At 1,000 megawatts, the wind farm would provide four-fifths of the maximum output of the proposed Central Maine Power Co. corridor slated for western Maine.

Longroad Energy also said the wind farm will help avoid about 1.3 billion tons of carbon dioxide emissions annually, equivalent to removing 260,000 vehicles from the road. The proposal will help Maine reach its climate goals of 80 percent renewable energy by 2030 and 100 percent by 2050, supporters have said.

How is Massachusetts involved?

Massachusetts agreed in January to finance up to 40 percent of the transmission and distribution projects in return for 40 percent of the generated energy.

Maine will purchase up to 60 percent of the energy. That distinguishes this project from CMP’s hydropower corridor, which was a response to a request for proposals from Massachusetts and comes at the commonwealth’s expense.

What are the costs and savings?

The cost of the transmission line is currently pegged at roughly $2.8 billion, although the wind power project is expected to provide a savings of $1.08 billion. On net, that comes out to $1.8 billion in costs over 20 years, according to the Maine Public Utilities Commission.

For Maine ratepayers, it is expected to cost $1 per month for 10 years. But a study commissioned by LS Power and Longroad Energy found it could save the average residential customer $2.30 per month. While the final projects are not yet approved, LS Power and Longroad Energy said they will also bring new jobs and tax revenue to the state and local areas.

What’s the timeline?

After LS Power hosted six town halls to receive feedback from residents, the company said it will consider tweaks to its route before the utilities commission signs off on any final plan.

Doug Mulvey, vice president of project development for LS Power, has emphasized “nothing is final” and said there is no deadline for a route. But he said the firm hopes to receive approval and other required permits by 2026 before completing the transmission line in mid-2028.

Longroad Energy currently plans on starting construction on the King Pine Wind farm in early 2028. Power would flow by late 2029 if all goes according to plan.

What’s the main criticism of the plan?

Critics do not like how the transmission line could cut through existing farms and residential properties, and they complained the Maine Legislature approved the plan in June before LS Power had shared its proposed transmission line route map.

The current map has two dotted-line sections that represent where LS Power is still unsure of its route, and a final decision will affect whether the line avoids certain towns or not.

Skeptics have also wondered why LS Power does not use existing transmission corridors operated, for example, by Central Maine Power. They point to a Twin States Clean Energy Link project traveling through Vermont and New Hampshire using state highways for a new underground line before coming above ground at an existing utility corridor in New Hampshire.

Mulvey, with LS Power, said a portion of the proposed route uses or parallels an existing transmission corridor, but to do so for the entire route, the company would have to demolish dozens of homes and build within 300 feet of about 100 additional homes.

As for complaints from farmers, Mulvey said less than one acre of agricultural fields are “permanently impacted by the alternative routes that we have proposed” and that transmission lines “successfully coexist” with farms in Maine and across the U.S.

“Landowners will be able to continue to use the easement area for a number of activities including farming, growing hay, pasture land, crossing the easement, hunting and the like,” Mulvey added.

Do you have unanswered questions about the proposed wind power line? Ask us below.would connect a massive new wind farm in northern Maine to the New England power gridwould connect a massive new wind farm in northern Maine to the New England power grid

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Billy Kobin is a politics reporter who joined the Bangor Daily News in 2023. He grew up in Wisconsin and previously worked at The Indianapolis Star and The Courier Journal (Louisville, Ky.) after graduating...