Homegrown energy has reached new heights with miscanthus, a 12' perennial grass. It's being tested in Illinois for use as a biomass crop and is passing with flying colors.
“There's really nothing fancy to managing miscanthus,” says Emily Heaton, University of Illinois graduate student. “You put it in the ground once, harvest it once a year after you're done with your other crops and you maybe give it a little nitrogen once a year.”
Miscanthus produces up to 20 tons of harvestable dry matter/acre/year. It's harvest-ready once the leaves fall off, the stems dry down and it becomes bamboo-like. But since it stands well in winter, Heaton says it can be harvested anytime from November through February.
Miscanthus, a native grass of Japan, is grown throughout Europe for biomass and should grow well throughout much of the U.S., says Heaton.
The bamboo-like canes can be chopped with a forage harvester. The dry canes can then be burned as a coal substitute. But the real profit may come from turning it into a substitute for natural gas, says John Caveny, a Monticello, IL, farmer with miscanthus test plots. He says Illinois researchers are working with a company that can gasify miscanthus, turning it into heat or a natural gas substitute.
“I just see a tremendous opportunity,” says Caveny. “It appears that once we grow this stuff, we've got more than one way to process it and convert it into an energy product or source.”
The tall grass is propagated from rhizomes because the commercial varieties are sterile.
“We don't want it to escape and become an invasive pest,” says Steve Long, University of Illinois plant biologist. “We consider it favorable that the miscanthus is sterile even with the added cost of propagation.”
Rhizome costs are about $128/acre, says Long. But that added cost is minor, considering a miscanthus stand will last at least 30 years, notes Heaton. The crop can sequester nearly 2 tons of carbon/acre/year in the soil. It burns with very low emissions of nitrous oxides and sulfur dioxide. Miscanthus just may fill the tall order of being a clean, renewable, sustainable source of energy.