A recent study shows that perennial grasses are economical biofuel crops to meet U.S. fuel goals and reduce greenhouse gas emissions. However, the West will have to contribute to the biofuels market in ways other than grasses. Tara Hudiburg, an ecologist in the College of Natural Resources at University of Idaho along with researchers from the University of Illinois, Colorado State University and the University of Georgia published their research in the first-ever issue of Nature Energy.

Hudiburg said the study is the most comprehensive to date focused on perennial grasses and one of the first to bring together economists and ecologists from around the country for a thorough assessment of whether grasses such as switchgrass and Miscanthus can reduce emissions and meet the biofuel demands of the U.S. Environmental Protection Agency’s Renewable Fuel Standard. The grasses can be used to make cellulosic biofuels.

Perennial grasses can supply the fuel needed to meet the RFS but only through smart land-use planning, said Hudiburg, and should not be planted in the West where other feedstocks are more sustainable and economical.

“These perennial grasses are not feasible environmentally for the West,” Hudiburg said. “Replacing greenhouse-gas-intensive crops — like corn grain for ethanol — is a much easier greenhouse gas problem to solve than replacing land out here.”

Hudiburg explained that much of the land in the West, such as forest land, is already positively contributing to emission reduction by storing carbon dioxide and other greenhouse gases rather than releasing them. The Midwest, on the other hand, is a net source of greenhouse gases, largely due to agriculture.

The study confirms, said Hudiburg, that perennial grasses are an excellent crop to produce biofuels and help reduce emissions in the Midwest and other areas. They are environmentally suited for much of the country and could allow second-generation biofuels to eclipse corn ethanol and reduce the amount of food-growing land used for biofuel crops.

Researcher Evan DeLucia from the University of Illinois added, “Greenhouse gas savings from bioenergy have come under varying levels of attack, and this paper goes a long way to showing that contrary to what some are saying, these savings can be potentially large if cellulosic biofuels from dedicated energy crops meet a large share of the mandate. This is a viable path forward to energy security, reducing greenhouse gases and providing a diversified crop portfolio for farmers in the U.S.”

The next step is to expand the research and examine the West’s role in reducing emissions while producing materials that can be turned into biofuels.