What is Hampshire County’s fair share of solar farm growth? Recent articles in the
Gazette have described proposals for ground-mounted solar installations around the
County; in Plainfield, Shutesbury, Amherst, Worthington and elsewhere. Many people
are paying attention to new state laws that will make permitting faster and are likely to
bring more projects our way. Many welcome these projects as our part of the transition
to a solar and wind powered future; others question these projects as too intrusive on
our communities. How much land area devoted to solar farms should we welcome?
The 2021 Massachusetts Climate Law established a timeline for achieving net zero
greenhouse gas emissions by 2050. The 2022 Clean Energy and Climate Plan for 2050
envisions 27,000 megawatts (MW) of solar photovoltaic installations. As of August
2025, Massachusetts has about 4500 MW of solar installed. So, let’s assume we need
about 22,000 additional MW of solar. The state has estimated that roughly 75% of solar will be ground-mounted with the rest on rooftops.
All that ground-mounted solar will require a lot of land. Consider the recently shuttered Mt. Tom coal plant in Holyoke. Its generating capacity was 136 MW. After its demolition, in 2019, a portion of the site, about 22 acres, became a solar farm with a generating capacity of 5.8 MW. To match the capacity of the demolished plant would require a solar farm covering over 500 acres, an area many times larger than that occupied by the coal plant. Our legacy electricity generation systems are mostly invisible to us; fuels are mined in faraway places and converted to electricity in central power plants such as two nearby natural gas plants; the 229 MW plant in Agawam, Hampden County or the 578 MW plant in Blackstone, Worcester County. There are no utility-scale fossil fuel power plants in Hampshire County.
Over the coming decades, about 1.27% of the land area of the commonwealth will need to be devoted to ground-mounted solar according to the state’s technical analysis for installation pathways. That translates to 66,000 acres devoted to solar. Taking this as a good estimate, how much of these 66,000 acres should be assigned to Hampshire County and its towns? What is our fair share? To begin thinking about this let’s look at two ways we might measure “fairness” and see how the numbers play out.
First, use land area. Solar is available everywhere and is inherently local; solar energy collection should be distributed more or less uniformly across the commonwealth. The
second approach is to use population. People use electricity; solar energy collection should be located in proportion to town and county population.
Using the first approach, we start with the fact that Hampshire County is nearly 7% of the total land area of Massachusetts; it follows then that the county is assigned 4,400 acres of ground-mounted solar. Hampshire County’s assignment can be distributed over its towns, again by land area. Selecting two towns with recent solar proposals, the fair shares for Amherst and Plainfield are approximately 220 acres and 170 acres, respectively.
Hampshire County is 2.3% of the commonwealth’s population. Using the population proportion approach, the assigned shares are approximately 1,500 acres for all of Hampshire County, of which 370 acres is Amherst’s share and 6 acres is Plainfield’s
share. Lightly populated areas have much smaller shares while populated areas are assigned larger shares. This approach may become impractical and raise environmental equity issues when we apply it to the large cities outside Hampshire County such as Springfield which would be assigned nearly 1500 acres for ground-mounted solar. The commonweath’s most densely populated city, Somerville, would be assigned an impossible 29% of its land area.
Both methods discussed here assign Hampshire County many more acres of solar than are now installed. The actual placement of ground-mounted solar projects in the towns and counties of the commonwealth will not follow a tidy formula like either of these two approaches or other formulas that could be devised. Each proposed project will be unique and may or may not deserve support. Every project will require the willingness of landowners to provide suitable land, the willingness of solar developers to make the financial investments, and the approval of permitting authorities. An additional ingredient to any proposal will be public reaction. I hope that, as we respond to these projects, we carry an understanding of the scale of the coming solar transition. What is our fair share? That is for all of us to decide.
David Ahlfeld is a retired professor of civil and environmental engineering who prefers
numbers over adjectives.