City wastewater treatment plant plugs into the sun


CLAREMONT — An array of dignitaries turned out at 9 a.m. on a rainy morning to cut the ribbon at the new solar array at Claremont’s wastewater treatment plant.

“The plant is the city’s biggest energy user,” said Assistant Public Works Director Victor St. Pierre. The solar array will produce 25 percent of the plant’s energy.

The project cost $328,000 to build and is projected to pay back its purchase price in 11 years, said St. Pierre, “unless Eversource raises the price of electricity, which they’ve been known to do.”

In that case the solar array will pay for itself sooner. Over the life of the array — 40 years — officials project it will save taxpayers more than $800,000.

The array feeds electricity directly to the wastewater treatment plant, which uses it immediately.

“We’re using all the power right here,” said St. Pierre. “Most of the energy is used during daytime here.”

With energy-saving measures supported by New Hampshire Department of Environmental Services, energy use at the plant can also be reduced substantially. St.Pierre said he was hoping that eventually the solar array could cover 50 percent of the plant’s energy needs in the future.

The array is built behind the plant on a hill that made with excess fill piled when the plant was built in 1980. With a power-purchase agreement between the city and Revision Energy, the solar array builder, the price of energy is locked in at a lower cost than any other source.

Consisting of 432 solar panels, the 151.2-kilowatt array is estimated to generate 190,522 kilowatt hours per year, off-setting over 200,000 pounds of carbon pollution — the equivalent of 10,000 gallons of gas.

Mayor Charlene Lovett thanked everyone for showing up and said the project is concrete evidence that Claremont is committed to lowering energy costs and protecting the environment. Senator Jeanne Shaheen couldn’t make it to the ribbon cutting, but she sent a letter applauding the project.

“This is a big step forward,” said Eric Ruderman of Revision Energy. “The New England power grid is straining to keep up with peak demand on these hot days. Solar reduces peak demand.”

Former Mayor Robert Porter later related the new power source to the plant it serves. He offered informal remarks about how people have become more accepting of environmental protections. Remembering the passage of the Clean Water Act in 1973, Porter said, “The rivers were sewers. I had the privilege of calling up the woolen mill and the paper mill and telling them they had to do pre-treatment before flushing their water into the river. Now everybody in this country takes it for granted that our rivers are not going to be sewers.”

Earlier this year, Claremont received the 2018 Energy Week Municipal Champion Award, recognizing the city’s efforts to reduce energy use and protect the environment.