Miscanthus, an Energy Crop for Illinois?

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Could Illinois agriculture someday produce a crop that would be burned to generate electricity? A group of researchers led by plant biologist Steve Long at the U of I thinks so. Building on studies and practical experience with biomass power generation in northern Europe, they are investigating the economic and environmental potential of growing Miscanthus x giganteus as an energy crop in the American Midwest.

Miscanthus is a perennial grass indigenous to East Asia, known most widely by its many ornamental forms, which grow in tall clumps and produce long, feathery flowers. The type of Miscanthus being investigated for use as an energy crop in Illinois is a stronger-stemmed, highly productive hybrid that attains a height of eight to twelve feet over the course of the growing season.

Miscanthus x giganteus is a sterile cross of two naturally occurring species, which is propagated by means of rhizomes. Unlike some ornamental varieties, which have escaped and become invasive, Miscanthus x giganteus does not set viable seed, and so is not a threat to native plant communities. (If you’re wary of such claims you might rest easier knowing they are substantiated by thirty years of experience with this type of Miscanthus in Denmark.)

For use as an energy crop, the annual growth of Miscanthus is left standing in the field to dry, and can be harvested from November into February, using the same machinery that is used to harvest corn. It is then bundled and fired in combination with coal. One of the benefits of burning Miscanthus to generate electricity in Illinois is that doing so would alleviate the need for power plants to import low sulfur coal from out of state in order to meet emissions standards, as they currently do.

From an environmental perspective, Miscanthus appears to hold a number of advantages over row crops such as corn and soybeans. As a perennial, it is established with a single planting operation, as opposed to the yearly tillage and planting required for annual crops. This greatly reduces soil compaction and erosion, and eliminates the costs and energy use associated with planting every year. Miscanthus also improves soil by adding large quantities of organic matter to it.

Added benefits accrue from the fact that Miscanthus is low input crop. It requires little to no herbicide once it is established because it comes up early in the spring and grows so thickly that it simply out competes weeds. It requires little or no fertilizer because it recycles nutrients back to its roots at the end of the growing season. And Miscanthus grows well even in dry conditions, which would likely obviate the need for irrigation.

Environmental benefits aside, the question for potential growers of Miscanthus will be whether they can make money doing it--and the answer to that question appears to be yes. In fact, the U of I team calculates that over a ten year period, and without subsidies to either system, Miscanthus production could be more profitable than a rotation of corn and soybeans, especially in parts of the state where corn and beans are least viable.