VASSALBORO — When the congregation at the Vassalboro Friends Meeting decided to make some energy-efficiency improvements to their 19th-century brick meeting house a few years ago, they also wanted to make a statement that would illustrate their Quaker principles.

This past week, that message went on full display, when workers installed 33 photovoltaic solar panels to the roof of the house on South Stanley Road.

The solar panels will meet almost all the building’s energy needs, but just as importantly, it demonstrates the group’s dedication to social and environmental causes, said John Reuthe, the congregation’s assistant treasurer.

“They have been wanting to make a statement that people need to focus on the environment and step up and take action,” Reuthe said.

Even though the roof siting isn’t ideal, the congregation was adamant the panels should be placed on the building prominently, not mounted to the ground behind the house. “It’s our way of saying there is climate change, and the way to do something about it is to reduce fossil fuels,” Reuthe added.

The “green” energy improvements fit into the congregation’s dedication to social justice. The Quakers have been meeting at the house since 1833, and the group emphasizes peacemaking through programs and activities such as building homes through Habitat for Humanity and raising money for an AIDS orphanage in Kenya and a Quaker school in Palestine.

But the green energy project was aimed closer to home.

After the deciding to install solar electric panels, the congregation members also wanted to make sure they were sourcing their materials from socially and environmentally conscious companies, by comparing manufacturers using a scorecard developed by the Silicon Valley Toxics Coalition. Chinese companies dominate the solar panel manufacturing market, and the Friends wanted to ensure the companies they selected protected the rights of workers and didn’t release toxins into the environment.

“That played into the selection. People said, ‘I’m willing to pay more if we use more socially conscious companies,'” Reuthe said.

The $26,000 investment was a big commitment for the congregation’s 50 active members. The Quakers come from every walk of life and aren’t wealthy, but the group’s consensus was that the project was worth the money.

“It’s a large investment from a small group of people,” Reuthe said. “Most everyone is struggling to make ends meet, but they thought it was important to do this.”

The congregation eventually settled on hiring Insource Renewables, a Pittsfield company, to install the panels. It completed the work Tuesday.

Almost all the equipment was built in the United States, with a few components from Europe, Reuthe said.

Before putting the solar panel showpiece into place, the congregation also was working on less attention-grabbing improvements to make the meeting house more efficient. It installed spray-foam insulation in the basement, put in new storm windows and hooked up two electric heat pumps.

As a result, the house’s oil use has gone from 400 to 500 gallons a year to less than 5 gallons, Reuthe said. The congregation wanted to wait for a severe winter like last year’s to determine how to scale the solar panels so they could provide enough electricity to heat and power the building.

“It’s sized for really significant cold weather,” Reuthe said.

The panels are expected to produce about 90 percent of the house’s electricity needs, he added.

Making sure the retrofit is noticeable fulfills another of the Quakers’ goals. They want to influence other churches and community organizations to consider investing in energy-efficiency improvements such as solar panels and building weatherization.

Humans have contributed to the environmental destruction of the planet, Reuthe said, and taking these kind of steps can make a difference.

“We may not be able to change the environment in our lifetime, but we can stem the bleeding,” he said.