For the last 25 years, Barron County, Wis., has been burning residential and commercial garbage and using the steam energy from its Waste to Energy and Recycling Facility to produce power and sell excess steam energy to the Saputo USA Cheese plant across the street. However, the facility still had additional generating capacity that was not being used.
In 2008, the facility manager, locally based ZAC Inc., started looking into the potential to use new technology to take advantage of the wasted energy. Last year, the facility installed additional flue gas heat-recovery equipment and a new condensing steam turbine generator. The system takes excess steam from the existing turbine to generate electricity, which is sold to the local utility Xcel Energy. Because of environmental requirements placed on waste-to-energy plants, the electricity produced at the facility is considered by both the U.S. Environmental Protection Agency and U.S. Department of Energy to be one of the cleanest forms of power available.
The new system started operating in January and is expected to generate 5.3 million kilowatt-hours of electricity annually, which is enough energy to power 532 average Wisconsin homes for a year. The $3 million project was funded by a $500,000 grant from Madison, Wis.-based Focus on Energy, Wisconsin utilities' statewide program for energy efficiency and renewable energy, and the county. The revenue from energy sales will offset approximately $3 per ton in tipping fees at the facility in early years. That will increase to $10 or more per ton after the principal and interest is paid off in 12 years.
At current rates, the system is generating between $800 and $1,000 on a normal day. Although a few start-up issues linger, the system output is at or above expectations.
For more information, visit the Barron County Waste to Energy website at www.barronwi.govoffice3.com, and watch a short video about the facility from Wisconsin Public Television http://video.wpt2.org/video/1938508766#.
Project: Green energy generation
Jurisdiction: Barron County, Wis.
Agency: Waste to Energy
Date completed: January 2011
Cost: $3 million