THE HEALEY ADMINISTRATION unveiled a new mapping tool on Thursday that suggests the state has the potential to generate an enormous amount of solar power.
In a press release, the governor’s administration said the mapping tool indicates that “Massachusetts has more than enough solar potential to support its decarbonization requirements – about 15 to 18 times what is likely needed. The top-rated parcels add up to double the amount of solar called for in the “2050 Decarbonization Roadmap.”
In more concrete terms, the mapping tool indicates the state’s solar potential is a whopping 506 gigawatts, with 56 gigawatts considered highly rated for development. Those numbers are way above the 34 gigawatts required under the state’s climate plan. Ninety percent of the potential solar would come from ground-mounted installations covering 1.6 million acres, according to the analysis.
While Healey’s press release hailed the state’s tremendous solar potential, one solar developer who served on the technical advisory committee that helped develop the mapping tool urged caution in evaluating the numbers.
Jessica Robertson, chief of policy and business development for solar developer New Leaf, said the mapping tool is only an indicator of solar potential, not a guide map to quick construction of solar installations.
The mapping tool assessed every tax parcel in the state for solar development, first determining whether installing rooftop, canopy, or ground-mounted solar is feasible and whether it is allowed under existing policy rules. Are wetlands on the parcel or is the parcel protected or paved? The analysis then graded each parcel for solar suitability. Is the land used for agriculture currently? Is the land critical to biodiversity? Is it facing the sun and is it close to an electric substation where solar power could be delivered to the grid.
While the analysis appears precise, Robertson said the data inputs have their limits. The analysis gives an A grade (for most suitable) to any parcel within two miles of an electric substation, but she noted most substations are at or near capacity now and adding new connections and new capacity can be very expensive and time-consuming.
“That’s all going to take a lot of time,” Robertson said. “That’s where their number [for solar potential] is going to get whittled down.”
Robertson said the mapping tool is a starting point for solar development, a broad-brush tool for finding the best locations. But she stressed that each location needs to be investigated to determine if it is actually suitable for development.
“The value of this is that it may be the platform for better policy-making,” she said, referring to the crafting of state subsidies for solar and giving municipalities the tools to zone for solar at the municipal level.
“This isn’t the final. This is the start of the process,” Robertson said.
The analysis was developed by the Department of Energy Resources working with an advisory committee of experts and a team from Synapse Energy Economics. The mapping tool was officially unveiled under a solar canopy at the Natick Readiness Center as part of an event celebrating the fifteenth anniversary of the passage of the Green Communities Act, which paved the way for the development of solar incentives. Fifteen years ago, Massachusetts had 3 megawatts of installed solar; today it has 4 gigawatts.
“With the study results, we can be strategic about where and what kinds of solar we deploy without sacrificing ratepayer cost, our natural resources, or our clean energy goals,” said Elizabeth Mahony, the commissioner of the Department of Energy Resources, in a statement. “This tool allows us to identify pockets where the most suitable solar potential is, and direct investment and resources towards prioritizing solar in those areas.”
The analysis of solar potential in Massachusetts comes at a time when the perception of solar’s importance to the regional power grid is changing. For years, solar’s impact has been difficult to track because much of the electricity generated by solar panels is used behind power meters and never makes its way on to the grid where it can be measured.
But solar is starting to have a bigger and bigger impact. Traditionally, power demand is lowest at night when people are sleeping and energy consumption is low. But increasingly the period of lowest demand is shifting to late afternoon on sunny days when solar power production is the greatest.
The operator of the New England power grid recently said its concerns about the adequacy of electricity supplies had lessened through 2027, in part because of stronger than expected solar power generation, flat electricity demand, and fewer retirements of existing power plants.
Grid officials said solar power was a nonfactor in the region in 2010, but it contributed 5,500 megawatts by the end of 2022 and is expected to double to 11,923 megawatts by 2032.