Clearing forests to build large-scale solar farms can deliver climate benefits, but those gains often come at a cost to nearby homeowners and ecosystems, according to new research from the University of Massachusetts Amherst.

The study, which will appear in the November edition of Land Use Policy, examined a proposed 9.35-megawatt solar project in Amherst, Massachusetts, to weigh the trade-offs of replacing more than 40 acres of forest with photovoltaic panels. 

Using a 20-year cost-benefit analysis, researchers found the project’s net benefits ranged from $2.7 million to $12.7 million, depending on assumptions about carbon pricing. Though the project has since been withdrawn from consideration, the research establishes methods that can be used to assess similar proposals across the Northeast.

The analysis calculated both benefits—primarily the reduction in carbon dioxide emissions by replacing fossil fuel power—and costs, which included reduced property values near the site, lost carbon storage and sequestration from trees, and diminished ecosystem services, such as air filtration and flood protection.

“From a societal-level perspective, you have positive net benefits, but a lot of the costs are borne by local actors,” explains lead author Christine L. Crago, associate professor in the Department of Resource Economics and the Commonwealth Honors College at UMass Amherst. “So, we have to balance our societal goals with the harm on these local communities.”

The study found that property value losses were the single largest cost, accounting for more than 70% of total impacts in the “all impacts” scenario. Homes within six-tenths of a mile of the project site were estimated to lose about 2% of their value, based on previous housing studies in Massachusetts and Rhode Island.

Despite these local costs, the researchers found the project’s climate benefits would be realized quickly. The carbon “break-even” point—when emissions avoided by solar power surpass those released by cutting down trees—occurs within the first year of operation. Over two decades, avoided emissions could exceed $4 million at standard carbon pricing levels.

Massachusetts has seen sharp growth in solar energy in recent years, ranking among the top 10 states for installed capacity. But nearly half of the state’s recent forest loss has been linked to solar development, sparking debate over land use and conservation.

“This study highlights an ongoing discussion about balancing renewable energy development with local resources management,” notes co-author Richard W. Harper, extension professor of urban and community forestry at UMass Amherst. “It has application for residents, professionals and decision-makers throughout Massachusetts, the New England region and beyond.”

The researchers suggest that policymakers consider compensation mechanisms, such as community benefit agreements, to offset costs to nearby residents. They also caution that the analysis excluded some factors that could not be quantified, including impacts on groundwater and wildlife disruption, which could be significant in certain locations.

“These issues are still enough to hamper a project, as we saw in this case and in many others,” adds Crago, who is also a faculty affiliate of ELEVATE, a graduate training and research program focusing on technical, social and climate challenges in the energy transition. “So, we have to find ways to address those concerns if we’re to move forward with solar deployment that is equitable.”

The study was also co-authored by Maryam Feyzollahi, a doctoral student in resource economics at UMass Amherst.