Erin Ailworth, May 27, 2010. The roof of National Grid’s distribution center in Northbridge is covered with about 4,700 solar panels, making it the largest solar-generating facility in the state and the first such project to be owned by a utility.
The rooftop array — capable of producing about a megawatt of electricity, or enough to power 200 homes — was built mostly with Massachusetts technology and expertise.
“It’s all good work for all the right reasons,’’ said Michael Monahan, business manager for Local 103 of the International Brotherhood of Electrical Workers union, who
se members worked on the project.
The Cambridge consulting firm Zapotec Energy Inc. was also involved, as was the renewable-energy developer Nexamp Inc. of North Andover. The panels were made by Marlborough-based Evergreen Solar Inc.
“These are projects that a utility is in a good position to take ownership of and build,’’ said Dan Leary, Nexamp’s president. “They own the electrical infrastructure.’’
This week, the panels will begin converting sunlight into power, said Ed White, a National Grid vice president.
The company also is moving forward with solar projects in Dorchester, Everett, Haverhill, and Revere that will provide an additional 4 megawatts of electricity-generating capacity, possibly by the end of the year. The Dorchester project won approval from Boston’s Zoning Board of Appeals on Tuesday; solar panels will be installed near the National Grid gas tank next to the Southeast Expressway.
“It really ties back to who we are and what we’re about . . . our message around renewable power and efficiency and providing customers greener alternatives,’’ White said.
National Grid’s push to build large solar installations stems from the state’s Green Communities Act, which in 2008 gave utilities the right to own up to 50 megawatts of capacity.
Western Massachusetts Electric Co. is also looking to build solar projects, according to documents filed with the state Department of Public Utilities, and has received approval.
Having more renewable energy available to customers — especially electricity generated locally — is a goal of Governor Deval Patrick, who wants Massachusetts to have 250 megawatts of solar power generating capacity by 2017. Currently, it has 28.1 megawatts, with more than 30 megawatts in the pipeline.
The electricity from National Grid’s project is expected to eliminate about 1.3 million pounds of carbon dioxide emissions annually, the equivalent of removing 400 cars from the roads.
The project is expected to cost less than the $6.5 million originally estimated, White said. Since 2008, when National Grid filed plans to build solar facilities, panel prices have dropped. Customers will pay about a penny a month more for the facility over two decades.