The more we learn, the more we realize that earth-friendly, renewable energy sources are right here – in Midwestern fields and forests – full of opportunity. Alliant Energy’s path to a greener future hinges on our ability to be innovative and pursue alternatives to traditional energy sources.

Alliant Energy has been a leader in the exploration of renewable energy sources for decades and when it comes to our commitment, we don’t just talk the talk, we walk the walk. Our generation portfolio is comprised of a variety of renewable energy sources such as wind, hydro, solar and biofuels – like biogas and biomass – with projects ranging from small on site anaerobic digesters to large scale wind farms.

Biomass includes things like grasses, waste-wood and corn stalks. Our work with biomass dates back to the late 1990’s when we began experimenting with switchgrass. We conducted a series of switchgrass test burns at our Ottumwa Generating Station in Ottumwa, Iowa between 2000 and 2006.

Nelson Dewey Test Burns

The work underway at Nelson Dewey Generating Station (NED) in Cassville, Wisconsin is a prime example of Alliant Energy’s commitment to exploring the technologies and costs associated with reducing our carbon footprint. In November 2009, the Wisconsin Department of Natural Resources (WDNR) approved a 12-month Research and Testing Exemption (RTE) allowing for the co-firing of biomass at NED’s two cyclone coal boilers.

The RTE allows NED to burn 20 different types of biomass, mostly wood, agricultural based pellets and native grasses. The early test burns have consisted of three different types of materials: hardwood chips, wood-plastic pellets (90/10 percent mix) and corn-fiber. While the initial test burns consisted of small percentages, the amount was quickly upped to five and then ten percent. The RTE allows for co-firing up to 20 percent biomass.

During these test burns we’re examining everything from environmental impacts, supply chain capabilities, material delivery and handling costs to the blending and combustion of biomass based materials to help us better understand the capabilities we have within our current system.

While we have no current plans to burn biomass at NED on a permanent basis, all of the information gathered from performing these test burns will be used as we continue to explore cost effective ways to reduce our carbon footprint in the future.

Biomass studies

Alliant Energy has formed some invaluable partnerships along the way as we’ve studied the potential of biomass. One of those is with the Southwest Badger Resource Conservation and Development (RC&D) Council - a nonprofit community development organization whose mission is to implement natural resource conservation, managed growth and sustainable rural economic development in the nine county area of southwestern Wisconsin.

Alliant Energy is helping fund two biomass projects that Southwest Badger RC&D is involved with. Both involve biomass as a potential fuel source, specifically switchgrass and woody biomass. Woody biomass is defined as snags, tree tops and limbs, coarse woody debris, stumps, undersized or “non-merchantable” stems, and brush.

The University of Wisconsin in Madison is participating in the switchgrass study also, which involves six sites, covering about 62 acres. Each demonstration plot is approximately 10 acres. There are differences in establishment of switchgrass across the test plots based on things like tillage, weed cover and seed mix.

In the woody biomass study, Southwest Badger RC&D is working with the Driftless Area Initiative and landowners collecting information from 21 sites to determine the harvesting cost and volume of available woody biomass on a per acre basis. The study has not looked at where or how the woody biomass is used after it leaves the property.

The 21 participating sites total more than 830 acres and include land from private landowners, the Army Corps of Engineers, the Wisconsin and Minnesota DNR, a nature conservancy in the state of Iowa and Vernon County, WI forest.