Central Maine Power Co. transmission lines in Pownal in August 2023. New England governors are calling for new lines and other upgrades that would enable the region to support more wind and hydropower. Robert F. Bukaty/Associated Press

The more populous southern New England states need electricity and northern Maine offers abundant opportunities to deliver wind energy from Aroostook County and hydropower from Canada.

Tie the two together with a more than $1 billion transmission upgrade, and renewable energy will flow without impediments to the rest of the region. And with the cost split among the six states, Mainers will reap tremendous benefits at a bargain.

That’s the first-of-its-kind pitch made by New England’s governors to the region’s grid operator. Together, the states want to solicit bids for transmission projects close to the Maine-New Hampshire line and Portland.

One approach could involve building two lines — one from Pownal to Hampton, New Hampshire, and another from there to Haverhill, Massachusetts — but ideas about how to increase transmission capacity could vary and do not need to follow that specific route.

“They see Maine as an entry point for NECEC and home for hydro, onshore wind and really, really, really long-term, a floating wind farm,” Dan Dolan, president of the New England Power Generators Association, said in referring to the New England Clean Energy Connect transmission line being built in western Maine.

“They look at Maine as one of the last areas of New England with a bottleneck, but it has so much potential,” he said.

ISO-New England, the grid operator, is on board with the idea.

Unlike the governors’ request, past transmission upgrade projects have followed a “structured process,” said a spokeswoman for ISO-New England. It issues regular studies that identify areas to replace aging infrastructure or meet higher demand, upgrade transmission capacity to reduce costs to consumers, and comply with state or federal transmission policies.

GREENHOUSE GAS POLICIES DRIVE CHANGES

More efficient transmission will be needed to carry electricity generated by wind and hydropower as Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont develop stricter rules to reduce greenhouse gas emissions.

Relieving future transmission bottlenecks between northern and southern New England — when demand for electricity outstrips capacity of the transmission system — and accommodating more clean energy in Maine are the two main objectives of the regional solicitation, said a spokesperson for ISO-New England.

An ISO transmission study and others show that bottlenecks between Maine and southern New England will persist and only worsen over time, the governors said. Even relocating generation south of these transmission points did not ease electricity bottlenecks, they said last October.

The upgrades are needed to avoid overloading transmission lines and transformers as residents increasingly rely on electricity to heat buildings and power vehicles, and as offshore wind and other renewable energy sources far from homes and businesses produce more of the region’s power.

“There is broad interest in addressing these long-standing system challenges, and strengthening the transmission system in Maine is a reasonable, measured first step toward the region’s needed transmission investment,” the governors said.

ISO’s manager of transmission planning, Dan Schwarting, said the agency will issue a request for proposals in March or April and give transmission developers six months to respond. Twenty-seven qualified companies have been vetted financially and for their expertise to apply, he said.

The intent is to create a “ready-to-go spot” to plug in transmission when it’s built, Schwarting said. Projects should be completed by 2035 or as close as possible in case of supply chain problems.

Schwarting said ISO and the governors’ group won’t know the cost until developers bring a proposal to the table. But a previous transmission study for a similar project pegged the cost in the billions.

“It would not surprise me if it’s that amount,” he said.

The states and grid operator hope the project will pay for itself with renewable energy, such as onshore wind, that would cut the use of costly and volatile fossil fuels such as natural gas, Schwarting said.

MORE MEGAWATTS AND A NEW SUBSTATION

The governors urged ISO to require the developer to increase the Maine-New Hampshire capacity to at least 3,000 megawatts, up from 2,200 MW, a 36% increase. And at another site, known as Surowiec-South, about 20 miles northeast of Portland, capacity should be increased to at least 3,200 MW from 2,800 MW, up 14%.

In addition, bidders should show plans to build a substation in Pittsfield that can accommodate at least 1,200 MW of onshore wind. Companies may propose alternative sites that would be more efficient and cost-effective, according to the proposal.

Afton Vigue, spokeswoman for the Governor’s Energy Office, said in an emailed statement that Maine, working with the region’s other governors, has advocated for “careful, regional solutions” to transmission congestion problems that leverage cost-sharing among neighboring states to reduce the costs paid by Maine ratepayers.

Jason Marshall, deputy secretary and special counsel at the Executive Office of Energy and Environmental Affairs in Massachusetts, said “targeted investments” to relieve long-standing constraints in the region’s system and unlocking affordable generation in Maine can provide broad benefits to Massachusetts and New England.

“This includes greater energy independence, enhanced system reliability and increased competition in our energy markets that helps drive down costs to residents and businesses,” he said.

While state officials are looking to boost transmission, two of the three renewable power projects that would feed into new transmission are a long way from happening.

Maine has been trying to stand up an offshore wind industry with a research array and commercial sites in the Gulf of Maine. The commercial sites in particular face strong headwinds from President Donald Trump, who opposes wind power and has halted further development.

State regulators in 2023 rejected a proposed 100- to 140-mile transmission line that would bring power from a wind farm in Aroostook County and are seeking new proposals. Central Maine Power won a federal commitment of $425 million to build it.

One project nearing completion is the 145-mile NECEC transmission line, which is expected to bring 1,200 MW of Canadian hydropower to the New England grid. More than 34% of construction is completed, and the project is expected to come online in 2026, Massachusetts officials said.

A transmission upgrade is different from previous projects that fixed more narrowly drawn problems, such as reliability or economic development, Schwarting said.

“This rolls them up into higher level view,” he said. “This the first one beyond a 10-year horizon.”