Solar energy projects across much of Massachusetts could hit a stumbling block because of faster-than-expected growth since last summer.
Under state law, utilities can only hook up so many solar energy projects to their systems under the so-called “net metering” cap, which limits the amount of excess power utilities have to buy back from solar installations.
In the part of the state served by National Grid, that limit may be hit today or tomorrow, which would force companies in the solar industry to rapidly readjust.
As of 1 p.m. Monday, 99.9 percent of the utility’s net-metering cap has been reached for private-sector solar projects. The public sector installation cap already has been surpassed, with nearly 10 megawatts of solar projects waiting in line. Other utilities are further away from their caps.
Over the past week, about 20 megawatts of solar power applications were approved in parts of the state served by National Grid, said Ryan Fahey, an employee of the Cadmus Group, Inc. which tracks how much capacity remains under the state’s net metering caps.