One executive asked Rutland’s mayor if he knew of a family that would be willing to serve as a guinea pig. He suggested Mark and Sara Borkowski, whose century-old house became the first of 161 homes and businesses to take part. Under the program, the utility provides financing for energy upgrades, which participants can pay back over time through their monthly bills.

Green Mountain has still invested in large-scale renewable-power plants, like the Stafford Hill Solar Farm — 11 acres of solar panels and battery banks spread over a landfill behind a town dump — and two wind farms. Those developments have come in for criticism from some residents and officials who object to living near noisy industrial machines and worry about marring the natural beauty that draws residents and visitors to the state. The critics include Gov. Phil Scott, a Republican who opposes putting wind turbines along mountain ridges.

But many customers say they are happy to be part of greening the area’s energy supply, whether for the financial savings, to reduce greenhouse gas emissions and slow global warming, or just to make sure the lights stay on in a power failure.

“It’s not really any different than being anywhere else,” said Alexis LaBerge, 27, who was one of the first to move into the low-income development in Waltham from an old house that guzzled fuel to keep the house and hot water heated.

Now, when the power from the grid goes out, as it did one night this spring, she does not have to worry about food spoiling in the refrigerator. “It’s definitely nice being brand-new and having the backup,” she said.