Center looks at prairie grass for fuel

By Jerry W. Kram
The Tallgrass Prairie Center at the University of Northern Iowa wants to produce electricity from an unusual source: prairie grasses. The center, along with Cedar Falls Utilities (CFU), obtained $300,000 in funding from Iowa's Power Fund to study the use of mixed prairie grasses as a fuel for the utility's power plants.

The center will study production methods on sandy, marginal soil on 100 acres at the Cedar River Wildlife Area, said Dave Williams, special project coordinator for the center. Building on research that showed mixed prairie grasses are more productive than stands of single species, the center will plant several different mixes of plants and compare the productivity of the different blends. Using a monoculture of switchgrass as a control plot, the study will compare blends of five, 16 and 32 different native prairie species. "All of these species will be native to Iowa," he said.

The amount of land included in this study will be much larger than previous studies. Williams said the project will more closely reflect conditions that farmers growing these grasses as energy crops will face.

The study is funded for one year, Williams said, but it is scheduled to be a five-year study, so researchers will be returning to the Power Fund for additional money. Besides measuring the productivity of the plots, Williams said the project would measure the amount of carbon that the plants sequester in the soil, and how harvesting timing and techniques affect wildlife.

CFU has two coal-fired power plants, one of which has been converted to run on 100 percent biomass fuel. The utility will experiment with converting mixed prairie plants into pellets and cubes that can be burned in the power plants. Based on the utility's previous work with switchgrass, it is estimated that the 100-acre plot will produce enough biomass for an eight-hour test burn in the power plant.