Acres of corn stand tall on both sides of a narrow country road in northwest Indiana. It’s late August and the crop is tasseling, its golden crown coated in dew droplets sparkling in the morning sun.
Off on the horizon, there is a different gleam, one that’s brighter.
Sprouting out of the corn like a super plant are four arrays of solar panels. They stand 20 feet high, towering above the stalks growing below. They look both out of place — technology juxtaposed with nature — and as though they have always been there. After all, both the corn and the panels are reliant on the sun.
“Either way, they are storing solar energy,” said Mitch Tuinstra, a professor of plant breeding and genetics at Purdue University. “One is storing them as electrons and the other in the plants.”
Tuinstra is one of several Purdue faculty and graduate students studying these solar arrays on the university’s research field, just a few miles off campus in West Lafayette.
Farmland is well suited for solar development of all kinds, for the same reasons it’s good for growing crops –– it’s largely flat, drains well and gets lots of sun. Grazing land for animals like sheep can also be a good fit for solar. But what makes these Purdue research panels different is that they haven’t taken farmland out of production –– they’re built overtop of the corn itself.
It’s a practice known as “agrivoltaics” or “agrisolar,” where active farming and solar occupy the same place instead of separate locations. The approach brings many complications that researchers are still trying to address –– but they see big benefits in trying to hone in on best practices.
Farmers who want to lease their land for solar as an extra income source will reap even more economic benefits if that land stays in production. Some approaches to agrivoltaics may even help the crops themselves, researchers say.
“We want to see if we can devise systems that have minimal losses in terms of crop productivity, while maximizing their electricity output,” Tuinstra said. “Instead of relying entirely on corn yields or prices or soybean prices, you can actually begin saying, ‘At $7 corn, this is how you should operate your system, and at $3 corn, this is how you should operate your system.’”
Moreover, he said, researchers want to see if the co-location strategy could be a salve to a growing strain between solar and farming in the Corn Belt –– where residents and towns are pushing back on what they see as industrialization in rural communities.
Solar potential in farm country
The stakes behind this effort are high: Solar power has a key role to play in reducing the greenhouse gas emissions, chiefly from fossil fuel-fired power plants, that are driving the increasingly deadly effects of climate change.
The U.S. Energy Information Administration estimates that by the year 2050 –– when the Paris Climate Accords say the world must reach net-zero carbon emissions to avert further climate catastrophe –– solar generation will account for 20% of net electricity generation in the U.S. That would be up from a mere 3% in 2020. The Biden administration is investing to get to that point, including billions under the Inflation Reduction Act for solar production and investment tax credits some analyses predict will kickstart massive growth in the sector.
According to Tuinstra, all these new panels can’t all be concentrated in the desert regions of the Southwest, for instance, because it would be highly inefficient to transmit that energy throughout the rest of the country. Instead, there needs to be localized buildout. That way, utilities and consumers can reap the economic and reliability benefits of renewables close to home.
A 2021 Department of Energy report concluded that by 2050, land equal to a maximum of 0.5% of the contiguous United States’ surface area would be required for project solar growth to help meet climate change goals. It may not sound like much –– by comparison, farms account for approximately 40% of all land in the United States –– but it would represent nearly 9.5 million actual acres. That's close to that of all the corn and soybeans planted in Indiana alone.
That federal report said a focus on “disturbed lands” –– contaminated or developed sites like capped landfills and old parking lots –– could help prevent over-reliance on “high-value lands in current use.”
But in the Midwest and the Corn Belt, the vast majority of viable land that could be used for photovoltaic energy generation is tied up in agriculture –– specifically row crops, Tuinstra said.
Concern for tradition
For some residents in areas where farmland is being eyed for potential conversion, solar is viewed as an eyesore and a threat to crops and the agrarian character of their communities.
In late August, the corn surrounding the Palo Community Center in Palo, Iowa, was more than six feet tall. Farmers would harvest the crop over the next month or so, just like any regular season.
But this year, something else joined them in the field: signs denouncing industrial solar. Next door, the community center was filled with residents awaiting the fate of a proposed 200-megawatt solar installation. The project would be sited on agricultural land near town. Its not agrivoltaics, but a more traditional approach where the panels would not sit above any crops.
Some attendees supported the projects; many condemned them. Most cited objections to taking cropland out of production. In the end, the complaints didn’t matter: The projects were approved the following week.
When several meeting attendees were asked if layering solar arrays over active farmland could be a viable compromise, many were skeptical.
“I doubt it very seriously,” said Robert Little, a 74-year-old electrician in town. He worked on farms his whole life, and comes from a farm family. Agrivoltaics could put those generational practices in jeopardy, he said.
“The biggest concern would be old family traditions,” Little said. “And the other conflict is that I don't think it could ever work.”
Communities and counties across the Midwest are saying no to solar — like in Indiana, where nearly a third of counties have ordinances restricting, if not prohibiting, renewable projects.
This skepticism is a big motivator for researchers who think agrivoltaics is the right win-win approach. Crops and panels can work in concert on the same sites, they contend, instead of competing.
“Solar won’t be as productive as if there was no agriculture, and the ag won’t be as productive as if there was no solar,” said Stacie Peterson, who oversees the Montana-based AgriSolar Clearinghouse. “But together, they can still be really important and add so much to help achieve all goals.”
But there are unresolved challenges like the shadows produced by solar panels. That’s part of what the team at Purdue is studying, Tuinstra said. The goal is determining the optimal spacing between arrays to keep excessive shadows from interfering with crop production.
Farmers in the Midwest may have an advantage over their peers in the Southwest because solar arrays tend to work more efficiently in less heat-intensive environments, said Dennis Bowman, a digital agriculture specialist at Illinois Extension.
“Having a cooler environment [with] plants underneath the solar panel that are transpiring moisture and providing a cooling effect will actually help increase the efficiency of the panels,” he said.
One federal program is exploring different types of agrivoltaics through roughly two dozen projects across the country. Some, such as in the southwest and northeast, are looking at growing different types of crops including leafy greens and fruits. Smaller plants –– specialty crops such as lettuces, tomatoes and berries –– are better suited for an agrivoltaic environment because they benefit from shade and require smaller equipment for planting and harvesting.
Still, professors like Tuinstra at Purdue and Bowman at Illinois want to know if the corn and soy that predominate in the Midwest will work, too. At first glance, the likelihood seems low: Planting and harvest requires more sun and bigger equipment. And farmers across Indiana, Illinois and Iowa plant roughly 56 million acres of corn and soy each year, compared to just a few hundred thousand acres of specialty crops.
Some studies are looking at developing different types of seeds and crops that are better suited for growing under solar. And Tuinstra said solar companies are reaching out wanting for ideas on designing the best systems to fit around planting and harvesting.
Trying to optimize both crops and technology, though, is putting researchers and developers in a chicken-and-egg loop: To get funding for projects and lower development costs, you need years of proof that they work. But to build those proofs of concept, you need money and affordability.
‘A different mindset’
Midwest Agrivoltaic Systems and its CEO Andrew Poor are doing their own research on developing cost-effective solar panel substructures, known as racking, that stand taller and farther apart than normal arrays. The idea is to accommodate row crops and farm equipment.
This need for additional materials and special designs is one reason that, anecdotally, Poor said agrivoltaics tend to cost more than traditional arrays.
But there is no “average” cost for agrivoltaics yet, Poor said, because very few large-scale projects have been completed in the U.S. And now, rising demand and limited availability of solar panels is driving prices up as well.
“It’s the Catch-22,” Poor said. “I’m always looking for funding.”
Poor’s company is currently working on smaller agrivoltaics projects with partners willing to pay for the cost of materials, hoping to eventually ramp up to more expansive production as data rolls in. But it’s tough to attract development partners in a field that remains relatively unproven.
“They seem just as leery as the farmers are when it comes to signing up for a project,” said Tyler Lloyd, the solar operations director of Midwest Agrivoltaic Systems.
Not every farmer is opposed. Those with combinations of row crops and livestock have proved more receptive to the idea of agrivoltaics, Bowman said. Newer farmers less tied to traditional growing and harvesting tactics may also be interested in the tech.
“The trend has been to get this big equipment, to farm a lot of acres, and to farm it fast in a timely fashion to get the maximum yields. And it may take a different mindset” to see solar proliferate on conventional farmland, he said.
Social and economic scientists on the Purdue research team are researching concerns surrounding agrivoltaics and how to address them with farmers using facts, Tuinstra said.
“If the communities are concerned philosophically [and saying], ‘We don't want to see these arrays in our space,’ that's entirely valid,” he said. “What the social science and economics groups need to be able to say is, ‘This is the value of having the system, this is what it does to your farms, this is how it improves sustainability of these communities.’”
For agrivoltaics to win a place in the typical farmer’s heart — and their fields — some attendees at the Palo, Iowa, meetings said they’ll have to see it to believe it.
“There's no way it's gonna work. There's no way,” said Doug Hanover, a 62-year-old carpenter who started working on farms as a teenager. “I'd want to see it proven.”
Tuinstra said: “That is what we are doing.”
'Secret sauce for the Midwest'
With mounting data, Purdue doctoral student Varsha Gupta predicts this approach to solar should be ready for widespread implementation within the next decade or two.
“No one is doing research like this because these crops are viewed as temperamental so people think it can’t be done,” Gupta said. “But if we can optimize crops like this, corn and soy, then we can do agrivoltaics with anything.”
While growing crops may be the ultimate goal, solar projects and farmers across the Midwest and Indiana are taking baby steps in the meantime when it comes to agrivoltaics.
The Mammoth Solar Project in northwest Indiana — just an hour up the road from Purdue’s research field — was the largest solar farm in the country at 13,000 acres when it was announced last year. The project, which is currently under construction, is not designed for row crops, according to Nick Cohen, the president and CEO of Doral Renewables, the project developer.
To widen the rows of solar panels by just five feet to allow for bigger equipment would require nearly 200 more acres to achieve the same electrical output, he said. Or to raise all the cables by three feet for the same reason would cost an additional $9 million.
That’s why Cohen said the project needs to be designed for crops from the beginning. Instead, his company is considering other ways of implementing agrivoltaics under and around the Mammoth panels.
“The challenge now is to find that value, and not just monetary value, but it’s about finding that secret sauce for the Midwest.” he said.
Doral is exploring how to do that. For example, they are looking at planting a smaller crop like blueberries under the Mammoth panels. Some of the local farmers that are leasing their land are also planting sweet corn and popcorn in the buffer areas normally left open around the solar farm.
In other areas, they are going to plant pollinator species under the panels — while not a cash crop, it still has environmental benefits, he said. Cohen said they are even looking at having sheep grazing under some areas of the solar project.
Both the pollinator plants and the sheep are “very good for the solar project because it’s a good way to manage the vegetation,” he said, rather than having to mow it.
It’s also good for farmers. Greg Gunthorp, a farmer in northeast Indiana with a sheep herd, said he is very excited about the possibility of grazing under solar panels. He said he’s been in conversation with a few different projects in the region about partnering up.
He sees it as a win-win situation.
“Sheep don’t harm the system: They don’t jump on the panels, and they don’t chew the wires,” said Gunthorp, who currently has about 500 to 600 ewes. “And the big benefit for us is access to affordable land, which is a real challenge.”
While agrivoltaics and sheep grazing are in their infancy in the region, Gunthorp said he thinks the potential is huge. He said they should have some sheep grazing on solar farms next spring and hopes to expand to 2,000 ewes by 2025.
Cohen agrees it’s just a matter of time: “When you think about the importance of agrivoltaics, it is important — incredibly so. People feel better when we are using as much of that land as possible.”
This story is a product of the Mississippi River Basin Ag & Water Desk, an editorially independent reporting network based at the University of Missouri School of Journalism in partnership with Report For America and funded by the Walton Family Foundation.
Call IndyStar reporter Sarah Bowman at 317-444-6129 or email at firstname.lastname@example.org. Follow her on Twitter and Facebook: @IndyStarSarah. Connect with IndyStar’s environmental reporters: Join The Scrub on Facebook.
IndyStar's environmental reporting project is made possible through the generous support of the nonprofit Nina Mason Pulliam Charitable Trust.
This article originally appeared on Indianapolis Star: Purdue leading research to grow solar and crops together in Corn Belt