From spring to fall, Michael Dennett spends his days transporting sheep from his family’s homestead in Jefferson, Maine, to graze at nearby solar farms. The flock that began as a gift for his wife — “really just [an] excuse for myself to get sheep,” he said — now works as a solar lawn service.
“If you’re a sheep, one of your biggest concerns … is eating grass in the predawn to, like, seven o’clock in the morning, and then hiding out for the rest of the day in the shade and just ruminating,” Dennett said. “They’ll spend the entire day under those panels, snoozing, walking around and kind of being lazy.”
Add some cropland to the mix, and it’s the type of pairing that’s likely to become more important as demand for clean energy to meet state climate goals causes pressure to produce electricity on agricultural land. Finding ways for solar and agriculture to coexist could help ease land-use tension that is already becoming common across New England, advocates for the idea say.
Maine may be uniquely positioned for this emerging field, known as agrivoltaics or dual-use solar. Nationally, most successful projects so far have involved extras like solar grazing or pollinator habitat alongside panels at small farms with low-lying, hand-harvested crops — precisely the type of farms that dominate much of Maine’s agricultural sector.
Supporters say the concept has the potential to boost farmers’ revenue, but it’s also a risky proposition, which is why they say the state should fund a pilot project to gather more information about what works and what doesn’t when pairing solar and agriculture in Maine’s climate.
Piloting dual use
Maine has no more than a few small-scale agrivoltaics projects currently underway, including a study of how solar affects wild blueberry harvesters. But policymakers have eyed the potential for dual-use solar and agriculture with interest.
A stakeholder group that looked at agriculture and solar siting issues as part of the state’s climate plan recommended funding for a dual-use pilot program, among other things. This proposal got broad support from state legislators this year but didn’t secure an appropriation for agency staff and resources after its passage.
This marked a setback for people like Ellen Griswold, the head of the Maine Farmland Trust. She sees dual-use solar and agriculture as an obvious win-win — providing economic and energy benefits to farmers, preserving a climate in which their crops can thrive, and making more land available to solar developers, all with fewer tradeoffs.
“I think there’s more hesitancy in Maine around dual use because it’s a newer concept … and so I think some people — farmers included, some agency officials — are a little bit more skeptical,” Griswold said. “To us, this pilot was really important because it’s a way of getting more projects established, and being able to … really gather the data and the research, to be able to sort of provide proof of concept, right, before we talk about ways of incentivizing it.”
Farmland in general is often eyed for solar for the same reasons it’s good for growing plants — it’s flat, sunny, well draining and often accessible to outside infrastructure. When it comes to dual-use agrivoltaics, studies so far suggest that small, shade-loving crops on smaller farms, harvested by hand or with smaller equipment, are the best fit.
These kinds of crops happen to be Maine’s specialty. Federal data shows the state’s highest-value commodity is potatoes, which grow low to the ground in Maine’s vast, relatively flat and rural northern regions.
Agrivoltaics research offers good news for potatoes. One study from Belgiumsuggests that certain arrangements of solar panels can cool potato plants and help them grow in a warming and drier climate, and found that potatoes under panels adapted remarkably well to lower light conditions. The plants are not always harvested by hand, though, raising questions about panel designs.
A diversified farm sector
Maine also grows major crops of its iconic wild low-bush blueberries and hay, often used to feed dairy cows. The state does have its share of corn but is less singularly reliant on it than many Midwestern states, where the tall crop tended by large industrial equipment carries challenges for solar.
The average Maine farm is less than half the size of the average farm nationwide. Whereas most farms across the country specialize in grains or cows, Maine’s largest source of farm sales in 2019 was “miscellaneous crops” — including lettuces, carrots, beans, peppers and strawberries, all low-lying, delicate plants that tend to be harvested by hand.