Clean Wisconsin Looks at Turning Some Corn Fields into Solar Farms

Friday, February 3rd, 2023 -- 8:01 AM

(By Joe Schulz, Wisconsin Public Radio) Converting less than one-third of the roughly 1 million acres Wisconsin uses to grow corn for ethanol into solar farms would boost the state’s energy production and help reduce carbon emissions, according to a new report from Clean Wisconsin, an environmental advocacy nonprofit.

According to Joe Schulz with Wisconsin Public Radio, clean Wisconsin looked at both the gross energy production and the energy "inputs" required for solar and ethanol production. It found that 88 percent of the energy generated by solar goes to society and 12 percent is offset by production requirements. For ethanol, only 20 percent of the energy goes to society and 80 percent is offset by production.

"Corn needs to be grown, harvested and processed into ethanol, all of which require energetic inputs. Likewise, solar panels need to be manufactured and installed," said Paul Mathewson, science program director for Clean Wisconsin. "When accounting for inputs, the net energy production of solar is over 100 times that of corn ethanol."

Mathewson said growing corn for ethanol also has a negative environmental impact on the state’s waterways because corn requires chemical inputs like pesticides and nitrogen fertilizer.

"Agriculture contributes to about 90 percent of the nitrate contamination problems," he said. "And corn needs a lot of nitrogen fertilizer to grow at the scale and at the intensity that we grow in Wisconsin."

Corn is the number one crop in Wisconsin, covering around 4 million acres of land in the state, about one-fourth of which is used for ethanol production, according to the study.

For comparison, the state has 3,500 acres dedicated to solar, less than 1 percent of the land devoted to corn for ethanol, researchers said. To achieve Clean Wisconsin’s target of net-zero carbon emissions by 2050, the state needs to build about 280,000 acres of solar farms.

"With just a fraction of what we're using already to grow corn ethanol for energy, we can produce enough homegrown energy (with) solar panels that would power our state's clean energy economy," said Chelsea Chandler, Clean Wisconsin’s climate, energy and air program director. "And we'd be improving our water quality, our air and our soil health at the same time."

Mathewson said farmers can receive annual lease payments for leasing their land out for solar projects, which would compensate for lost profits from corn.

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