The move will see more customers with solar PV installations gain credits for the extra power they generate and feed back into the grid for use by others. According to the Solar Energy Industries Association (SEIA), it clears the way "to deploy more solar, reduce energy costs for customers and create more jobs in the state”.

Under the previous 2008 law, the state’s major electric utilities were required to make net metering available to customers until the total programme capacity reached 3% of the utility’s peak demand. Parts of the state reached that this year, effectively stymieing continued solar investment, according to the SEIA. The 2012 Energy Act doubles participation in the programme to 6%, split equally between public and private energy projects.

Carrie Cullen Hitt, Vice President of State Affairs at the SEIA, said: “Already this summer, we’ve seen record high temperatures driving electricity demand through the roof. By clearing the way for more solar, we’re putting that same sunshine to work producing much-needed energy, local jobs and a cleaner environment.”

However, Hitt said the new Act could have been better. “The Legislature failed to address a critical property tax issue, causing some uncertainty for solar energy consumers and developers,” she said. SEIA will work with the Massachusetts Municipal Association, the Patrick Administration and the Legislature to resolve the issue, she said.