Harvesting the Sun TwiceInside the experiment to help farming and solar power work together.

The grass was greener under solar panels.That simple observation set Oregon State University researcher Chad Higgins on a path to become a global authority in agrivoltaics: the practice of combining solar energy production with agriculture.

More than a decade later, OSU is a world leader in this growing field, and Higgins — an associate professor in the College of Agricultural Sciences — is still focused on grass. But now his question is: What conditions always make grass greenest? The answer could be transformative for family farms, rural communities and a world with an exponentially growing demand for food and energy.

The basic idea behind agrivoltaics is that solar panels and plants have a symbiotic relationship. Plants need only so much sunlight before they become stressed and start to sweat — increasing water use and reducing productivity. Strategically placed shade can yield healthier crops with less irrigation. In turn, vegetation cools the air beneath solar panels, improving efficiency and extending panel lifespan.

Ideally, it could be a win-win-win benefiting food, water and energy systems simultaneously.

But the knowledge of how best to set up this relationship is still a work in progress. In April 2023, OSU completed a five-acre agrivoltaics installation at the North Willamette Research and Extension Center (NWREC) near Aurora. For the first time anywhere in the United States, scientists could study the relationship between solar panels and agriculture in a space designed for that work, rather than conducting what Higgins calls “experiments of opportunity” under existing solar arrays.

Now OSU faculty and students are experimenting with a cornucopia of crops. Still, what works in Oregon may fail in Minnesota. Higgins knew testing every crop in every microclimate would be impossible. That brings us back to grass — orchardgrass, specifically.

Common in the Willamette Valley, orchardgrass is used for pastures, hay and erosion control. But more importantly, grass is a global reference crop: its growth patterns align predictably with more than 200 other crops. Higgins realized that if he could isolate the effect of agrivoltaics on orchardgrass, determining the optimal combination of growing factors — precisely how much water + nutrients + sunlight/shade = greatest yield — that equation could then be applied broadly. That’s huge.

On a January morning NWREC tour, the test plot — two years into a three-year effort — looked like, well, a frosty, grassy field. But to Higgins, it’s a field of dreams. That same week, The Oregonian reported on a study commissioned by regional utilities, warning that within five years, the Pacific Northwest could face energy shortages severe enough to cause rolling blackouts.

Illustration by Matt Twombly

Solar Grazing

Agrivoltaics works with pasture land as well, offering shade to grazing cows and sheep. Goats, however, are discouraged because of their tendency to chew and climb equipment.

Harvesting Watts

The five-acre North Willamette Research and Extension Center (NWREC) has an installed capacity of 320 kWh , enough to power 40 homes.

Recharging Wells

One OSU experiment tests whether rainwater from panels can replenish groundwater.

Built to Move

Panels are programmed to automatically rotate so they stay pointed at the sun, maximizing sunlight exposure. They can also be angled up to allow farm equipment through.

Revitalizing Soil

Aside from crop studies, an intended 20-year experiment is exploring whether agrivoltaics can improve soil health and remediate damaged land.

Reimagining Farming

Higgins’ golden rule: Don’t block the row. Make space for tractors by ensuring that panels aren’t close to fences and that cables are buried deep enough to allow cultivation.

As society wrestles with how best to use limited land and secure the three foundational elements of modern life — food, water and energy —  Higgins suggests “the narrow path to thread the needle is agrivoltaics.”

To be sure, big policy questions remain — like who would pay for the technology. But first we need to nail down the science, and that’s what land-grant universities do best.

Higgins’ passion is to help family farms survive. Once a first-generation college student from Upstate New York dairy country, Higgins understands the pressures farmers face. Farms have always harvested solar energy, he noted. Agrivoltaics harvests it twice.

“This is a way to increase farm profitability and sustain viability for another season,” he said. “People say, ‘I don’t believe you, Chad; it doesn’t add up.’ I say, ‘Come and visit, come drive the tractor through. Believe the evidence of your own eyes.’”