Report: Massachusetts has ample solar power potential

By Michael P. Norton and Sam Drysdale

STATE HOUSE, BOSTON, JULY 6, 2023…..Massachusetts has more than enough solar energy potential to support the decarbonization requirements enshrined in state laws, according to a report officials released Thursday.

The Department of Energy Resources report found the state’s land parcels possess about 15 to 18 times the solar energy potential needed to fulfill decarbonization targets by 2050.

A narrower group of the state’s best-rated parcels alone could support up to double the amount of solar capacity called for by the middle of the century, researchers found.

“Because of the amount of suitable solar potential identified, we can be aggressive with our solar policy while balancing land use priorities and protecting our natural resource,” the Department of Energy Resources concluded in its report.

State climate action plans released in 2022 estimate that between 27 and 34 gigawatts of solar energy would be required in 2050 to reach decarbonization goals, or more than 10 times the amount of solar currently installed in Massachusetts. Those few dozen gigawatts of solar energy are part of a broader effort, alongside building out reliance on wind and hydroelectric energy, to achieve net-zero carbon emissions statewide by 2050 as required by law.

To meet these ambitious goals, the state will have to triple or quadruple its current annual rate of solar installations, researchers found.

In the past five years, Massachusetts has developed solar at a rate of about 0.3 GW per year. The state will need to increase this rate to 1 to 1.3 GW per year to reach its goal by 2050, the report says.

Between January 2018 and August 2022, 1.283 GW of solar capacity was installed around the state.

Cambridge-based Synapse Energy Economics Inc., which prepared the report for the state, estimated that Massachusetts’ technical solar potential is 506 GW — 15 to 18 times greater than the amount required by 2050. About 30 percent of that amount, or 152 GW, is on land identified as “highly suitable” for solar.

If the full 506 GW of technical potential solar was built, it would generate about 13 times the current demand for electricity in Massachusetts, the report says.

Even as the state pushes to increase solar development, the effort can run into local opposition.

Debates pitting clean-energy supporters against conservationists — both of whom might dub themselves environmentalists — are happening on the local level across the country. Some community activists fight against large solar installations in their towns, arguing that it is counterintuitive to cut down trees or cover open land to put up solar panels.

Synapse analyzed three main types of solar developments for the study.

Rooftop solar panels can be installed on residential rooftops as well as on commercial or industrial buildings; ground-mounted solar is the most common type for large-scale “solar farms”; and canopy solar panels are built above parking lots to still allow cars to drive and park below while providing shade.

Ground-mounted solar has the most “highly suitable” potential, according to the report. It estimates that 60 GW alone could come from large-scale farms (requiring 1.3 acres of land or more), and 39 GW from smaller ground-mounted land parcels.

There’s also untapped potential from rooftop solar, which Synapse estimates could deliver 40 GW of power from close to 1.9 million parcels around the state.

Canopy installations have the least potential — though still not insignificant, with 83,335 parcels identified as suitable, to create 14 GW of power.

The study identified these appropriate areas for development by considering if the land already has agricultural uses, if it is important for biological diversity, if the area is of critical environmental concern or a wellhead protection area, how much carbon dioxide would be emitted by building solar on the land, how close the parcel is to electric infrastructure, and if the terrain is well-shaped for solar development.

“In total, 10 percent of all technical solar potential (52 GW) scores an A (most suitable) in every category,” the report says. “Because Massachusetts will need 27 to 34 GW of solar to meet [Massachusetts Clean Energy and Climate Plan] limits by 2050, 100 percent of needed solar could in theory be sited in the most suitable (all A’s) parcels.”

The report includes a caveat that the suitable parcels for rooftop and canopy development is likely to be overestimated. The study only considered how close each of these parcels was to electric infrastructure, not other potential barriers.

Additionally, the report said the state’s solar siting policies should align with its existing goals for land use and natural resource management.

The Clean Energy and Climate Plan includes goals of permanently conserving 40 percent of natural and working lands by 2050, and it calls on the state to develop solar policies in a manner to protect critical habitats and limit tree clearings.

“This study shows that with careful and coordinated planning and robust community engagement, the Commonwealth can build the clean energy infrastructure needed for economy-wide, net-zero emissions by 2050 while avoiding most impacts to nature and people,” said Steve Long, director of policy and partnerships at The Nature Conservancy in Massachusetts. “We can both generate and transmit clean energy and meet our net zero goals while protecting sensitive natural and working lands and waters and the valuable benefits they provide including protecting biodiversity, enhancing climate resilience, and fostering natural systems to store and draw pollution from the air.”