A new solar farm is being developed on land owned by the University of Wisconsin southwest of Madison with the aim of finding a better balance between green energy and agriculture.
The loss of hundreds of acres of farmland has been a growing point of local opposition when solar developers pitch new projects in Wisconsin and across the country.
It doesn’t have to be that way, said Josh Arnold, campus energy advisor for the UW-Madison Office of Sustainability. To begin to prove that point, the university is working with Alliant Energy to design a 2.25-megawatt solar farm on its Kegonsa Research Campus near Stoughton as a laboratory for a multi-disciplinary study of agrivoltaics — the co-location of solar energy and agriculture.
Alliant will lease 15 acres of the nearly 300-acre campus to build the 2.25 megawatt solar array, which will produce enough electricity to power about 450 homes when it goes live later this year.
The project grew out of classroom research projects and ongoing talks between the utility and the university about ways to get the campus to zero carbon.
The university’s goal is not just to reap the benefits of solar energy, but also to help chart a path to maximize the use of valuable farmland, and in the process allay some of the opposition to solar developments, said Arnold, who is leading the project.
“When we were thinking about some of the key concerns in Wisconsin, more and more communities have questions about how can we continue our agricultural tradition and our agricultural practice and also embrace our clean energy future?” he said. “And we started to think that maybe it isn’t an either-or, maybe it could be a both, and maybe there’s a way that we can combine solar with agriculture.”
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Finding Wisconsin-focused solutions
Agrivoltaics isn’t a new concept.
It’s been put into practice in other places, including on a solar farm operated by Vernon Electric Cooperative, where the utility has partnered for years with a local farmer to graze sheep. Beekeepers set up hives near solar fields, which are often seeded with mixes of plants attractive to pollinators.
Other universities have also studied it, but those efforts have largely been in places like Colorado and Arizona on arid lands that don’t translate directly to Wisconsin’s climate and soil conditions.
In addition to the UW research project, Alliant has separately partnered on an agrivoltaics project with Iowa State University. Both aim to develop more locally applicable approaches to mixing solar and agriculture.
“Thinking about how we can showcase innovation in addition to ideas that could be used within other places in Wisconsin is really a key thing,” Arnold said.
In June, the university announced the research team led by Steve Loheide, a professor of civil and environmental engineering, would receive a $500,000 Research Forward grant. The grant program supports innovative and groundbreaking research at the University of Wisconsin–Madison.
Will Fulwider, a regional crops educator with UW Extension, is particularly interested in the possibilities of grazing sheep and finding the best combination of forage plants for cover and nurtients. Fulwider said plantings that are typically done on solar farms generally focus on pollinator habitats, but the seed mixes aren’t developed specifically for the Midwest.
“If we want it to be agricultural in the sense of how people in Wisconsin typically understand agriculture, we need to reconsider the plants, the vegetation that we’re going to grow underneath,” Fulwider said. “We’re actually putting together a fact sheet for people that are interested in solar grazing in the Upper Midwest based off of our math, and what’s cool is the ability to then test that at a site like this.”
The researchers recognize that using sheep as natural lawnmowers can work on smaller sites, but it’s not an agricultural solution for utility scale solar farms, which span thousands of acres. Those sites won’t again be planted in corn — the height of corn and the equipment needed to harvest it make it a bad fit.
Could robotic harvesters work under solar panels?
That’s where a more ambitious idea comes into play — Arnold and the researchers envision partnering with companies to develop smaller, robotic harvesting equipment, perhaps for hay, that would be able to fit between and even under the solar panels.
“I think that would make light bulbs go off in people’s heads,” Fulwider said. “I think farmers would be like, I want to be the farmer that gets that contract for the 6,000 acres, because I’m gonna be able to put up a lot of hay. And I’m gonna get paid to do it, because I’m also the vegetation manager.”
David DeLeon, president of Alliant Energy’s Wisconsin energy company and senior vice president of operations, said he hopes the research will result in ideas that can be applied to utility-scale solar projects.
“Our hope when we got involved with UW on doing research is better implementation and utilization of the land and to maximize the benefit to the community,” he said.
More:Wisconsin’s first new wind farm in 6 years went online in April. Why did it take so long and what does the future hold for wind energy?
A three-part approach to research, education and outreach
The solar farm will be built with three distinct areas for different uses.
One section, with fixed, south-facing solar panels, will be open to the public for outreach and tours by school groups, community members and others who want to learn about solar power.
A central zone that will have single-axis trackers that move to follow the sun and are typical of utility scale projects, and the third zone will have tilting panels that are lower to the ground.
The latter zones will lend themselves to different types of research, and the focus of that work will likely evolve over the 20 year or longer life of the solar installation.
“The problem of agrivoltaics is one of these issues that touches so many different disciplines,” Loheide said. “I think that one of the parts that I’m most excited about is bringing together folks from the social sciences, physical sciences, biological sciences, law, policy and all across campus to work on this. And I’m optimistic that we’ll find good solutions, because the researchers and the students really want their work to have an impact.”
