Solar Plus Agriculture Protects Farmland, Improves Panel Efficiency

Rows of solar panels with crops growing in between | Oregon State University
Oregon State University
Published On
Feb 18, 2021

Oregon State University’s Nexus of Energy Water and Agriculture Laboratory (NEWAg), Corvallis, Ore., is partnering with the Oregon Clean Power Cooperative to build an agrivoltaics research farm that will co-develop land for solar energy and agriculture.

“Agrivoltaics provide a rare chance for true synergy: [improved land-use efficiency], more food, more energy, lower water demand, lower carbon emissions, and more prosperous rural communities,” stated a recent NEWAg study in the journal Sustainability.

The study found that widespread installation of solar arrays on farms could provide 20% of the United States’ total electricity generation, if less than 1% of the nation’s annual budget was invested in rural infrastructure. It also said agrivoltaics could reduce carbon dioxide emissions—the equivalent of removing 71,000 cars from the road annually—and create over 100,000 rural jobs.

The intermittent shade from photovoltaic (PV) panels is still conducive to growing crops, and, in some cases, may even help some grow better, such as lettuce, according to a 2013 article in Agricultural and Forest Meteorology. The variable shading forms a unique microclimate that alters “the local hydrology and ecology underneath the solar canopy,” according to NEWAg’s website.

Previously, Chad Higgins, NEWAg assistant professor, found that in a sheep pasture with solar panels, grass beneath the panels used water 300% more efficiently and grew 90% more forage, according to an article in Capital Press.

Sheep grazing on forage growing underneath solar panels | Oregon State University
Sheep grazing on forage growing underneath solar panels | Oregon State University

Dan Orzech, general manager for Oregon Clean Power Cooperative, explained that another unexpected advantage of agrivoltaics is the cooling effect from the crops, because solar panels generate electricity more efficiently in cooler temperatures. Temperature-related panel degradation is also reduced, which may extend the life of the panels, he explained.

The research farm, expected to produce 700-800 kilowatts of energy, will be located on approximately 6 acres and will be the first field-scale research site designed to study the impact solar panels have on agricultural land, crops, livestock, soil health, water use, plant physiology and crop yields. It will also encourage sustainable farming practices, such as on-farm fertilizer production, electric tractors and precision agriculture, Orzech said.

Higgins said the cooperative will start growing cold vegetables between rows of solar panels, and then move to perennials and fruits that experience sun damage.

“We can try to strategically place the trellis to take away that sunburn for the fruits,” he explained.

The farm’s PV panels will be arranged in two common designs, to make it more useful for commercial solar developers: (1) standard, single-axis trackers and (2) south-facing fixed-mounts elevated 8 feet, high enough that people and machines can work underneath.

For the past three years, the Oregon Clean Power Cooperative has developed community solar projects throughout the state. It provided funding to buy and install the research farm’s solar arrays, and it plans to generate revenue by selling subscriptions to the power it generates through Oregon’s community solar program. Its community investment model allows people to make minimum investments of $1,000 in solar projects throughout the state, while also adding grants, tax equity investments and other sources of financing to the mix.

The university will subscribe to 40% of the power from the research farm, while nearby churches, nonprofits and homeowners are also expected to participate.

There is increasing conflict nationally between solar projects, farming and land conservation interests, since priorities for preserving prime farm ground often clash with renewable energy goals. In 2019, for instance, Oregon’s updated land use rules made it difficult to site solar projects on agricultural areas and prime farmland.

“For decades, farm ground has been taken away by urban development,” Orzech said. “People don’t want to see farm ground turned into parking lots and buildings. We think it’s a false conflict because the two [agriculture and solar projects] can cooperate and benefit each other.”

Joint solar and farming could actually help states achieve their renewable energy goals. Oregon’s Renewable Portfolio Standard requires the state to produce 50% of its electricity with renewable energy by 2040.

“Eventually we’ll have to revisit the rules,” Higgins said. “My thought is why not do both? There’s no fundamental reason why you can’t continue farming underneath solar panels. Agriculture has control of the land. It doesn’t take much of that land in dual-use to actually make some severe dents in our green energy targets.”

About the Author

Marlena Chertock

Freelance Writer

Marlena Chertock is a former editorial intern at Electrical Contractor magazine who now writes for the magazine as a freelance journalist. Her articles have appeared in The Washington Post, Marketplace, NBC News, News21, WTOP and The Gazette. Contact...

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