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Hydropower Transmission Proposal That would Run Through NH Under Consideration

Published Monday May 8, 2023

Author Hadley Barndollar, NH Bulletin

Twin State screenshotA screenshot of the Twin States Clean Energy Link website homepage. (Screenshot)

A newly proposed 211-mile transmission project bringing Canadian hydropower through Vermont and New Hampshire – dubbed the Twin States Clean Energy Link – is currently under consideration by the U.S. Department of Energy for federal funding.

The $2 billion partnership between National Grid, Citizens Energy Corporation, and Northeastern Vermont Development Association would bring 1,200 megawatts of clean, dispatchable energy to New England – enough energy to power nearly 1 million homes. In New Hampshire, the partners say, the project would utilize a majority of existing transmission corridors and infrastructure, along with some new, buried lines.

News of the Twin States Clean Energy Link proposal comes just as a state jury in Maine ruled unanimously last month that the 145-mile New England Clean Energy Connect, a controversial $1 billion hydroelectric transmission project connecting Canada and the region, can proceed – despite a Maine state voter referendum in 2021 that essentially blocked the project. 

The proposal also comes five years after Eversource’s 192-mile Northern Pass project was nixed by the state’s Site Evaluation Committee, following years of proceedings and delays. Northern Pass would have also delivered hydropower from Canada, but through the construction of 180 miles of new power lines. 

In a statement Wednesday, Gov. Chris Sununu called the Twin Links Clean Energy Link a “low-impact plan” that’s a “win-win for families and businesses across the Granite State.”

“New Hampshire is always looking to put solutions on the table that lower energy rates for consumers, and the Twin States Clean Energy Link makes use of clean, renewable energy to do just that,” Sununu said.

Here’s what we know so far about the Twin States Clean Energy Link based on the information publicly shared by National Grid, Citizens Energy Corp, and Northeastern Vermont Development Association. 

Twin States map
A map shows where the Twin States Clean Energy Link transmission project would cross into New Hampshire from Vermont and run down the state to Londonderry. Yellow is the existing overhead transmission corridor while green is underground cable along state roads. (Screenshot)

Where would the Twin States Clean Energy Link be located?

At the Vermont-New Hampshire border, there would be an underground crossing below the Connecticut River, connecting to approximately 26 miles of new underground lines along Route 135 from Dalton to Monroe. From there, nearly 110 miles of upgrades to the existing transmission corridor from Monroe to Londonderry would take place.

There would also be a new converter station built in Monroe on the site of the Comerford substation, upgrades to the Dunbarton substation, and a new substation in Londonderry. 

What would the climate impact of the project be?

Project partners say the Twin States proposal would reduce New England’s carbon output “by millions of metric tons per year,” while furthering growth of the region’s clean energy economy. 

Hydropower, according to the U.S. Department of Energy, is one of the largest sources of renewable energy, using the natural flow of moving water to generate electricity. Hydropower currently accountsfor 31.5 percent of total U.S. renewable electricity generation and about 6.3 percent of total U.S. electricity generation.

While hydropower is considered clean energy, it can affect the environment via its dams, reservoirs, and the operation of hydroelectric generators. 

The Twin States transmission system would operate bi-directional, meaning New England could export excess power back to Quebec during periods of low customer demand. 

Where will the power go?

After crossing into New Hampshire and running south, the energy would reach a new substation in Londonderry, where it would ultimately interconnect to the New England regional power grid, operated by ISO New England, to be used by customers across the region.

Who is paying for this?

Costs to develop the Twin States Clean Energy Link would be paid for by utility companies that deliver energy over the line, meaning ratepayers would eventually be on the hook. However, the project partners say, “the energy the project would deliver will result in lower costs for New England energy customers.”

Environmental impacts

On the project website, the partners address questions about environmental impacts, saying the transmission line crossing the Connecticut River will be buried underground below the riverbed via a horizontal direction drilling system. 

For parts of the project buried along roadways, the project design “is intended to minimize environmental and visual impacts.”

Environmental and archaeological studies will be conducted throughout the permitting process if the project receives approval from the U.S. Department of Energy. 

Local community benefits programs

National Grid and Citizens Energy Corp. say they will create “extensive community benefits programs.”

“Overall, the project is expected to provide many more millions in overall benefits to Vermont and New Hampshire towns and cities, including environmental justice communities, along the project route,” the website says. “Our goal is to work with communities and local economic development partners to understand how our benefits program can be tailored to support local needs.”

National Grid and Citizens Energy Corp. expect to hold “detailed listening sessions” to determine how the Twin States project “can maximize its benefits for the region.”

The project is estimated to generate hundreds of millions in new property tax revenues for cities and towns through which it passes. Over the first 40 years of operation, the website says, Twin States is projected to contribute millions more in lease payments to Vermont and New Hampshire for underground burial of the lines along state roadways.

Next steps

The Twin States proposal has been submitted to the U.S. Department of Energy’s Transmission Facilitation Program, a competitive program providing $2.5 billion in funding as part of the Infrastructure Investment and Jobs Act.

The project partners say federal funding is “critical” in order to move forward on the project with the current timelines in mind. 

More from Gov. Sununu

Sununu has submitted a letter of support to the Department of Energy. During press availability on Wednesday, he said the project “absolutely aligns with what I’ve been championing.”

Asked further about potential citizen opposition based on past history in the state and recent events in neighboring Maine, Sununu said, “You’re always going to have folks that are trying to stop a lot of these projects going forward for whatever reason, you know, small advocacy groups or whatever it is. There’s a process for them to have a voice. But there’s also a process for… to make sure that we’re moving forward. One of the biggest crises in this country right now is the fact that it can take 10 to 15 years to permit a transmission line. But everyone wants to plug things in.”

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Reporter Ethan DeWitt contributed to this story.

This story is courtesy of NH Bulletin under creative commons license. No changes have been made to the article.


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