You could drive by it 1,000 times and never see Warren's newest, and currently its second largest, solar array. It's on top of the mill buildings at 30 Cutler St.

For several months, officials with Ecogy Energy in Brooklyn, NY, have been working with local installers to build the 250KW solar farm on the mill's flat roof surface. The mill's David Wescott said it was interesting to watch the workers install the panels, which aren't fastened to the roof structure but instead ballasted down with substantial weight. Rather than power the mill itself, the energy producer rented the rooftop space  and will sell electricity from the array into the grid.

"It's nice to be able to do it without having to cut down any trees," Mr. Wescott said.

Apart from a large commercial solar farm in Touisset, the 30 Cutler St. array is currently the largest in Warren. There is an approved plan to build a much larger array on the site of the Windmill Hill golf course on Schoolhouse Road, but that project is some ways away from completion.

Mr. Wescott said the array is pretty much complete at this point. He plans to host a ribbon cutting party with Ecogy Energy later this month.