For decades, the American corn monocultures have fueled an industry—corn ethanol—that promised to make gasoline cleaner. That promise has failed. But a new study suggests these sprawling fields could still play a powerful (though very different) role in America’s energy future.
By replacing just a sliver of the land used to grow corn for ethanol with solar panels, scientists say, the United States could dramatically boost its renewable energy production while restoring critical ecosystems and providing new income streams for farmers. This would offer clean energy, reduce pollution, and make way more money for farmers than current practices.
In a paper published in the Proceedings of the National Academy of Sciences on April 21, a team led by Matthew Sturchio at Cornell University proposes a simple yet radical solution: harvest the sun, not just the soil.
Small Changes, Big Impact
The idea of using agricultural fields in tandem with solar panels isn’t new. But when it comes to ethanol, in particular, the numbers tell a striking story.
Today, about 12 million hectares—roughly the size of New York State—are devoted to growing corn for ethanol. According to the study, converting just 3.2% of that land to solar facilities would quadruple the nation’s utility-scale solar energy production, raising it from 3.9% to 13% of total supply.
“We demonstrated that even small injections of ecologically informed, highly efficient solar in vast cropland landscapes, largely used to produce ethanol fuel, can lead to great potential benefits for people and planet,” Steven Grodsky, senior author of the study, said in a release.
The benefits are multi-sided. Solar panels, when installed alongside fields of perennial plants, could help filter farm runoff, stabilize soils, and create much-needed habitats for bees, butterflies, and birds. “By envisioning energy development as a part of ecosystems, we can begin to recognize socioecological trade-offs that can inform sustainable land-use change,” Grodsky said.
In fact, the researchers say, this could usher in a new type of farming.
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A New Kind of Farming
Growing corn for ethanol is widespread in the US, but it’s always been a rather controversial practice.
Initially, it’s intended to curb carbon emissions. However, corn ethanol’s climate benefits are very debatable. Some studies suggest it may even be more carbon-intensive than gasoline when land-use changes are factored in. Corn also demands heavy irrigation, fertilizers, and pesticides, exacting a toll on water quality and soil health.
Solar energy, by contrast, requires far less land for the same energy yield. Sturchio’s team found that one hectare of solar panels could produce as much energy as thirty-one hectares of corn-ethanol crops.
“Solar has a bunch of different end uses,” said Matthew Sturchio, first author of the study. “Energy going to the grid could go to a home, your car, your phone, your computer, anything that’s electrified.”
Using spatial analysis, they mapped locations across the Midwest—within two miles of existing transmission lines—where solar panels could be installed without costly new infrastructure. For farmers, leasing a small portion of land for solar panels could generate three to four times more revenue than growing corn for ethanol.
A Path Forward for the Midwest—and Beyond
The study’s implications stretch beyond the Midwest’s corn belt. As the demand for ethanol wanes—driven by the rise of electric vehicles—the need to rethink the use of farmland becomes more urgent. Meanwhile, electricity demand could surge by as much as 75% by 2050, according to projections.
The researchers envision a broader energy transition where croplands could also yield electricity and ecological health. In regions such as the Mississippi River Basin, where fertilizer runoff fuels massive “dead zones” in coastal waters, replacing some cornfields with solar arrays surrounded by perennial vegetation could cut nutrient pollution dramatically.
By converting about 391,000 hectares of cornfields into solar farms, the U.S. could not only replace the energy content of its entire ethanol production but also prevent roughly 54.8 million kilograms of nitrogen and 26.3 million kilograms of phosphorus from entering waterways.
Such changes would ripple outward, fostering more resilient agricultural landscapes better able to weather the stresses of climate change. Enhanced pollinator habitats could boost the yields of fruits, vegetables, and other crops that depend on bees—a win-win for farmers and ecosystems alike.
In fact, if 46% of the current corn-ethanol land were transitioned to solar, it could meet all of the U.S. 2050 decarbonization goals related to solar energy.
What the new research makes clear is this: amid the golden fields of the Midwest, a greener, more resilient future may already be taking root—if we are willing to plant it.