After two years of analysis, University of Minnesota researchers have clarified how Minnesota might help the U.S. reach its energy goals.

The Renewable Fuel Standard mandates that the country use 36 billion gallons of renewable fuel per year by 2022, up from 16.55 billion
gallons in 2013.

The University researchers analyzed energy use predictions from the Environmental Protection Agency, the Department of Energy and the Department of Agriculture, focusing on the expected production of
different biofuels.

This research found that different agencies made different assumptions about biofuel prices, land availability and implementation costs, said bioproducts and biosystems engineering assistant professor Jason Hill.

All three agencies differed in crop location, which Hill said is an important clarification for researchers, policymakers and biofuel investors. If the researchers had not figured out there was this difference, other scientists might only use one agency’s predictions and their conclusions would
be misled.

“Our group is looking at the environmental impacts of biofuels,” Hill said. “We need to understand the future of what that’s going
to look at.”

“It helps us tease out the benefits and negatives,” BBE graduate student Brian Krohn said. “Some of those … lead to a U.S. landscape that’s better for the environment, and some of that leads to landscapes that have a very high negative impact.”

Two crops being considered to meet energy demands are corn stover and perennial grasses, which together may compose at least 10 percent of
biofuel production.

Currently, Krohn said, corn stover — the remnants of corn stalks and leaves — is left on the fields because it maintains soil structure. But farmers who remove too much corn stover and sell it for biofuel could deplete the nutrients in the soil unless a conservation
policy is enacted.

“There are realistic concerns about [biofuels’] impact on water and air,” Hill said. “What was learned in our previous work is that how you produce biofuels matters in terms of their effect and from what sources matter for their effects.”

For example, BBE PhD student Bonnie Keeler said to avoid soil erosion, farmers can monitor how much corn stover they harvest from their field.

Based on the analysis of the agency predictions, Minnesota could be a large contributor of corn stover or perennial grasses.

“If corn stover becomes a significant player in ethanol,” BBE PhD student Tom Nickerson said, “Minnesota will have a pretty big role in producing ethanol for America.”

Corn stover production could be beneficial or detrimental, Keeler said, because it could increase revenue for farmers, but it could also replace
valuable grasslands.

The USDA predicted Minnesota could produce a significant portion of perennial grasses. Minnesota farmers could increase revenue by switching out hay or other crops for these grasses, Keeler said.

“Infrastructure and jobs come along with changing those, as well as environmental impacts,” she said.

But not all the reviewed predictions claimed Minnesota’s farmland would play a role in biofuel production. The USDA didn’t predict any corn stover would be grown in Minnesota, and the DOE and the EPA predicted no production of perennial grasses.

The future of biofuel production depends on understanding both the positive and negative impacts of all predictions, Krohn said, and they are
just predictions.

“There’s always tradeoffs,” he said. “No pathway is perfect.”