Large-scale research project in Ohio examines how solar energy and agriculture can coexist – The Advocate-Messenger

By Kathiann M. Kowalski

Energy News Network

Research currently being conducted at a solar farm in Madison County, Ohio, aims to shed light on how well multipurpose agriculture can work at scale. The answers will help develop best practices for future projects while addressing some concerns raised in ongoing debates about siting large solar projects in rural agricultural areas.

The more than 1,900-acre, 180-megawatt Madison Fields project will be one of the largest test sites for research into agrivoltaics – essentially farming between the rows of photovoltaic solar projects.

Farmers who want to lease land for solar power to diversify their income sources could use this approach to maximize their income and fend off opposition from critics who fear that solar power generation will render prime farmland unusable.

Some farmers have also said that income from clean energy can help them keep their farms running despite pressure from housing developers. A recent report from the American Farmland Trust says Ohio could lose more than 518,000 acres of farmland to urban sprawl by 2040.

That number dwarfs the roughly 95,000 acres of certified and other projects listed on the Ohio Power Siting Board’s most recent Solar Case Status Map.

But solar projects generally require large tracts of land all at once, while urban sprawl happens piecemeal over time, said Dale Arnold, director of energy policy at the Ohio Farm Bureau. Helping people understand and appreciate that is “absolutely great,” he said.

Savion, a subsidiary of Shell, developed the project in Madison County and began commercial operations on July 11. Amazon is the long-term buyer of the energy, but work to prepare the site for research by scientists at Ohio State University, Savion’s subsidiary Between the Rows and others began much earlier this year.

“People have a lot of questions about future energy development in this state,” Arnold said, particularly when it comes to setting aside land for agricultural production.

But today’s industry is increasingly shifting away from coal toward a diversified portfolio of natural gas, nuclear, hydroelectric, wind, solar and other types of generation. Projections also show that demand for electricity will increase through the middle of the century, he said.

“Finding a balance where you can do multiple things on the same land – in this case, both energy production and agricultural production – is obviously a big challenge,” Arnold said. If agrivoltaics is to become more than just a buzzword, both farmers and solar project developers need to establish best practices.

A big issue is which plants are well suited to large utility-scale projects. Compared to most solar farm projects in the Eastern and Piedmont states, utility-scale solar projects in Ohio and other Midwestern states can span 1,000 acres or more, Arnold said.

“You hear a lot about fruits and vegetables and specialty crops,” says Sarah Moser, Savion’s director of agricultural operations and agrivoltaics, for example. But growing them on 1,000 acres is “hard.”

Hey, you!

Moser and the researchers at Ohio State University believe that forage crops such as alfalfa and hay are promising. Cultivation could be expanded to cover large areas, says Eric Romich, an energy development specialist at Ohio State University Extension. And the plants would not grow too tall between the panels.

“We also wanted something that we believed was potentially economical,” Romich said.

Two 2023 reports by Ohio State University Extension researchers found that growing hay and alfalfa between rows of solar panels was feasible and that the nutritional value of the crop was good. However, this small-scale work at Pigtail Farms in Van Wert County used data from only a few test plots and control areas, an important limitation, Romich said.

The work at Madison Fields will now show whether similar results can be achieved on a larger scale. Part of a $1.6 million grant from the Department of Energy will help fund the work over a four-year period.

Further research will test how well plants grow in sun versus shade, Romich said. That’s important because some of the land between the solar panels will always be in shade.

The researchers planted the plants in test and control plots this spring and plan to start collecting data next year. “Forage plants are pretty finicky when it comes to establishing themselves,” said Braden Campbell, a wildlife scientist at Ohio State University who is also working on the project. The team has found compacted soil around the solar panels, “but we’re relieved that the seeds we planted in the soil are growing,” he said.

Moser plans to work with other crops as well. One example is soybeans. They have been used as a cover crop before alfalfa and hay were planted. Soybeans can also be integrated into a crop rotation when forage crops need to be replanted every few years.

“The market is there for it and it thrives,” said Moser, as it is a robust crop that can also loosen the soil and provide it with nutrients. Local communities have also expressed interest in the plant.

Send the sheep in

Other work at Madison Fields is exploring supplemental grazing. The goal is to harvest the forage crops as efficiently as possible. But vegetation control under and around panels and other infrastructure will still be needed, Campbell said. So after harvest, the sheep will go to work.

“To me, that’s three goods we can get from a single piece of land,” Campbell said: Solar panels will generate electricity. Growing hay and alfalfa will provide a harvest. And the land will feed sheep, which can produce meat, milk and fiber.

Other solar farms already use sheep for vegetation control or plan to do so. But “there is a big difference” between using sheep for vegetation control and relying on sheep for food, Campbell said.

Studies need to test the health of sheep using supplementary pastures compared to other sheep. Other questions include determining the optimal grazing rate of sheep per hectare and other logistical issues. But first, forage needs to establish good roots so it can withstand grazing pressure.

Tractors and more

A third research focus under the Department of Energy grant will focus on agricultural equipment. Tractors and other farm vehicles must fit between rows with their attachments. In the agricultural sector, there is a trend toward wider equipment that can cover larger areas more quickly but may not fit between rows of solar panels, Moser said.

“But many farmers still have smaller equipment,” Moser continued, because some plots aren’t suited to wider machines. Maneuvering 15-foot-wide equipment works pretty well, and 17-foot and even 20-foot widths can still work.

“I could get my 20-foot drill in there,” Moser said. “I just have to be careful.”

Arnold speculated that some companies might develop specialty equipment that allows attachments to fit more easily under the rows of solar panels. Other options could include raising or even leveling the panels when agricultural equipment is in use, he suggested.

Not only does farm equipment have to drive through an alley between two rows of solar panels, it also has to turn around at the end to enter another alley, Arnold said. So there has to be a sufficient turning radius without cables blocking the path of farm vehicles. Poles, stands and other equipment must not block the path of farm equipment either, he said.

The research results can help to design future solar projects so that they are “ready-to-use” sites, says Romich. At the same time, agricultural operations should not jeopardize the safe and efficient operation of a solar plant. “It’s a functioning power plant,” says Romich.

Arnold has further questions about infrastructure needs: What facilities are needed for drying, pressing and storing animal feed? What facilities are needed for other crops? And how will these be transported by truck to the markets?

What equipment and facilities will be needed for the sheep to be kept on site? This includes fencing, water etc. And where will their owner live?

“You have to have full-time staff there,” Arnold said.

Precision agriculture

The Ohio State University researchers, Moser and others also wonder how well precision agriculture can work with solar farms. The term refers to methods that rely on technology and data to guide farmers’ work. The spectrum of technologies includes remote sensing of field conditions with drones, soil sensors, automated weeders and more.

The big question is which precision agriculture technologies are well suited to crops grown between rows of solar panels as they generate electricity.

What the studies will show is unclear until the data is collected and analyzed, Romich said. Ultimately, he believes the results will provide a better understanding of what will work and what won’t.

Economic questions about business models, contractual agreements and more also need to be clarified, said Arnold. Ultimately, farmers have to make profits if agriculture and solar projects are to merge successfully.

“The possibilities are truly limitless” when it comes to business arrangements, Moser said. “My motto is always, ‘The farmers figure it out.’ And by working with them, we’ll figure out how to make it happen with the best practices.”