Made in the Shade: The Promise of Farming with Solar Panels
President Biden has set a goal of cutting U.S. greenhouse gas pollution by at least half (from 2005 levels) by 2030 and achieving net-zero emissions in the electricity sector by 2035. If the country is to meet these targets, solar power is going to have to play a big part.
And according to the U.S. Department of Energy’s latest Solar Futures Study, solar may well be supplying us with as much as 40 percent of our electricity by the middle of the next decade. But this hopeful scenario poses a conundrum. Scaling up solar to that degree would require a lot of photovoltaic panels—which, in turn, could take up a lot of land. How do we install them without fundamentally altering the physical character and functionality of our landscapes? Must scaling up mean contributing to energy sprawl?
Maybe not.
Recently, the field of agrivoltaics has emerged to explore ways of incorporating solar arrays into farmland without sacrificing that farmland’s arability, effectively allowing landowners to cultivate crops and generate clean energy harmoniously at the same time. Research indicates that growing crops beneath photovoltaic displays can actually yield a distinct set of agricultural and environmental benefits. Thanks to the shade provided by the panels, for example, the soil can retain more water, meaning it needs less irrigation. Panels can also help protect crops from hailstorms, high winds, and severe cold and heat, making them less vulnerable to extreme weather events. There’s even evidence to suggest that certain crops actually grow better, stronger, and longer under the protective covering of solar panels than they might otherwise, especially in hotter, more arid growing environments. As the already-hot-and-sunny parts of the world become even hotter and sunnier, the implications are enormous—for the climate, for crops, and for the farmers themselves.
A farmer’s annual income can be unpredictable. But by leasing their land to solar developers, farmers can put extra money in their pockets during good years and give themselves a much-needed degree of economic security during bad ones. Meanwhile, as the demand for renewable energy continues to skyrocket, solar developers have an equally strong incentive to seek out as many acres of wide-open, sun-kissed farmland or pasture as landowners are willing to rent out to them—including acres that might no longer be used for growing crops. This, at its essence, is the problem that agrivoltaics aims to address.
Agrivoltaics in Action
When Byron Kominek first approached officials in Boulder County, Colorado, about the idea of putting a photovoltaic display on his small family farm in 2018, he was surprised when they initially balked at his request. The county has aggressively pursued clean energy, and the city of Boulder has even committed to getting 100 percent of its electricity from renewable sources by 2030. Still, Kominek says, their “environmental conservation mindset” meant that “they were trying to conserve as much farmland and open space as they could, because they didn't want everything to turn into strip malls.”
As progressive as they may have been, the officials saw the infrastructural requirements associated with solar power as incompatible with maintaining the integrity of agricultural spaces. But things changed once Boulder County analyzed its clean energy projections more closely. “They totaled up all the power that rooftop solar would produce and found that it wouldn't even come close to providing all the power that the county consumes,” Kominek says.
After finally getting the green light to install solar, Kominek was busy trying to find the right balance between panels and plantings when he first heard about agrivoltaics from a friend of a friend who worked at the National Renewable Energy Laboratory in nearby Golden. He was immediately attracted to the idea. Now, three years later, Jack’s Solar Garden—named after Kominek’s grandfather, who first owned and worked the land—hosts more than 3,200 photovoltaic panels on about a sixth of the farm’s 24 acres, providing 1.2 megawatts of electricity, enough to power nearly 300 homes.
But even more impressive is what’s taking place under those panels. In the 2021 growing season, its first, Jack’s Solar Garden produced more than 8,600 pounds of organic vegetables, all of which grew beneath the cool, partially shaded “awning” of the photovoltaics. As of this writing, Kominek’s venture is the country’s largest commercially active agrivoltaics project. The solar garden functions in equal parts as a community farm, an education center, and a laboratory: a place where experiments can be conducted, effects can be observed, and the data can be recorded…right before being sautéed with a splash of garlic-infused olive oil and eagerly devoured. (Food grown under Kominek’s panels is harvested and distributed to the community by Sprout City Farms, a Denver-based nonprofit that promotes food system resilience and sustainable urban agriculture.)
Solar Is Blooming
Agrivoltaics, also referred to as “dual-use solar,” is already well known in a number of European and Asian countries, most notably Japan, where nearly 2,000 agrivoltaic installations currently generate more than 200 megawatts of electricity—enough to power more than 32,000 homes—and provide cover for more than 120 kinds of crops. In this densely populated country where agricultural land is relatively scarce, dual-use solar is expanding rapidly as farmers, clean energy advocates, and officials learn more about its benefits.
Here in the United States, agrivoltaics is also progressing, albeit more slowly. Ethan Winter, the Northeast solar specialist for the American Farmland Trust, which advocates for the protection of agricultural land and livelihoods through sustainable farming practices, is optimistic about dual-use solar’s prospects. “It has the potential to keep farmers farming, or even bring new farmers in,” he says, “and to stabilize a land base that might otherwise go to more permanent forms of development.”
Winter adds that by tweaking the crops-under-panels formula a bit, landowners are also learning how they might benefit from other ecosystem services that agrivoltaics provides. Introducing pollinator-friendly plants, for example, can create habitat for beneficial insects such as bees and butterflies. Planting native vegetation can improve soil health by reducing erosion. “If done right, it could actually be a way to build soils,” Winter says. “There’s a regenerative angle that’s interesting.”
Fascinatingly, research shows that the benefits of agrivoltaics cut both ways—that putting plants beneath solar panels can actually improve the performance of the panels, not just the plants. Because extreme heat negatively affects the efficiency of photovoltaic cells, they tend to generate more energy when the space around them is cooler. Placing abundant vegetation under panels leads to an increase in ground shade and humidity, which, in turn, leads to cooler photovoltaic cells and higher energy yields. One recent study found that panels with vegetation beneath them generated 10 percent more energy than those that had been placed over gravel.
Mind Your Ecosystem
Kominek and Winter are quick to point out that agrivoltaics isn’t a silver bullet. Its benefits, while real, are region- and plant-specific. It won’t work everywhere, with every kind of vegetation. “You have to be thinking about what you’re growing, and what the light requirements are,” says Winter. “Strawberries are different from corn, which is different from hay, which is different from kale.” And Kominek—whose experience inspired him to form a nonprofit dedicated to research and education around dual-use solar, the Colorado Agrivoltaic Learning Center—emphasizes that the climate of the given farmland is a big factor. “You probably won't see the same things happening in Maine that you see in Tennessee, and you won't see the same things happening in Tennessee that you see in New Mexico,” he says.
They also stress the need for incentives and market mechanisms geared toward farmers who want to pursue dual-use. Winter notes that the U.S. Departments of Energy and Agriculture have both recently made significant investments in agrivoltaics research, which he sees as a promising sign that some sort of large-scale federal aid may be on the way. Citing the many different Energy Department–sponsored loan programs, he imagines a set of criteria that—if met by landowners—would qualify them for preferential financing of dual-use projects, easing the significant up-front barriers to entry. “That would send a very clear signal to the private sector that we can lower our costs and capital.”
In the meantime, it may fall to small, independent farmers like Kominek to keep spreading the word and providing proof of concept. “I think it's always better to try and do something more than just what's standard—to try and do what's better not just for my family but for the community,” he says. His farm is a shining example.
Author : Jeff Turrentine
Source: https://www.nrdc.org/stories/made-shade-promise-farming-solar-panels
