For second time, Concord cancels solar project at wastewater treatment plant

  • A truck load of biosolids sit ready to be hauled away at the Hall Street Wastewater Treatment Plant in Concord on Wednesday, Nov. 29, 2017. (ELIZABETH FRANTZ / Monitor staff) Elizabeth Frantz

Monitor staff
Published: 8/18/2021 5:30:04 PM

For the second time an attempt to help power Concord’s wastewater treatment plant with solar panels has fizzled, this time due to questions about money, although a proposed new state law might make it feasible again.

“The city remains very hopeful that the governor will sign HB 315 that will allow the city to set it up somewhere. … There’s an opportunity for a project of significant scale,” said Beth Greenblatt of Beacon Integrated Solutions, the energy consultant for the city.

The city council’s Energy and Environment Advisory Committee reported July 28 that city staff had decided to discontinue any Hall Street solar project, two years after official announced plans to put a 2 megawatt solar facility near the treatment plant, which is a huge user of electricity. The decision followed considerable discussion between the city and ReVision Energy, the New Hampshire firm that bid on the project, about finances and ownership, including a proposal to shrink it to half a megawatt and install it “behind the meter.”

Greenblatt said technical details about rate structures and compensation and long-term contracts, complicated by the fact that the city buys its electricity not from Unitil but from a company called Constellation, undid the finances.

“We had long conversations with the utility, with the PUC (Public Utilities Commission) about ways to make that happen,” she said.

Sam Evans-Brown, executive director of Clean Energy New Hampshire, said this shows why New Hampshire lags behind neighboring states in solar installations.

“This is the second go at trying to get a project that really ought to be the type of thing we’re prioritizing; on disturbed land, no not-in-my-backyard issues, right next to a very big municipal load,” said Evans-Brown. “It’s just a perfect project and the fact that it hasn’t materialized twice speaks to the policy environment that these municipalities are trying to operate in. It would be a slam-dunk in any other state, but it’s hard to make them pencil out when you don’t have the policy.”

“This is why we don’t have more solar jobs in New Hampshire,” he said. “It costs tens of thousands of dollars in man-hours and studies to get a project to this point, then have a potential customer back out is really hard on those developers. … That’s why national scale companies don’t bring their jobs here to the Granite State.”

Greenblatt noted that complications over excess electricity production would be solved if the project had enough batteries to store that power so it can be used after the sun sets. Batteries are increasingly being added to solar farms for this very reason.

In 2016, Concord canceled a proposal to build a 2 MW plant near the treatment plant, partly because of questions about putting it on farmland.

Wastewater and water treatment plants are often the biggest electricity users in a municipality and it is increasingly common for cities and towns to reduce that cost by putting solar panels nearby. Peterborough, which is about one-seventh the size of Concord, installed a 944-kilowatt array near its plant, and Portsmouth and Nashua are also pursuing plans.

The biggest complication with the recent Concord project, Greenblatt said, involves what to do with excess electricity. On sunny afternoons a project of any size would sometimes have generated more power than the treatment plant needed at that moment. This excess would be sent into the power grid where it could be resold to other users.

Electric utilities, which own the poles and wires, pay for that excess power through a process known as net metering but there is constant debate about how much they should pay and, in this case, even who should pay – Unitil or Constellation. New Hampshire has a relatively low cap of 1 megawatt on net metering projects, which is one reason the 2 megawatt project was canceled. One megawatt, or 1,000 kilowatts, is the power needed to supply roughly 700 to 1,000 New Hampshire homes.

HB315 would raise that limit to 5 megawatts for cities and towns, which is why officials hope that it will allow them to come back with a bigger project with better financial return.

Gov. Sununu, who has a history of vetoing pro-solar-power legislation, has indicated he will support this bill but has not scheduled a signing date.

(David Brooks can be reached at 369-3313 or or on Twitter @GraniteGeek.)
David Brooks bio photo

David Brooks is a reporter and the writer of the sci/tech column Granite Geek and blog, as well as moderator of Science Cafe Concord events. After obtaining a bachelor’s degree in mathematics he became a newspaperman, working in Virginia and Tennessee before spending 28 years at the Nashua Telegraph . He joined the Monitor in 2015.

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