The boilers in Marvin Windows and Andersen Windows factories have been fueled by sawdust from the plant floor for years.
"The boiler system's run exclusively with waste material," said Susan Marvin, president of Warroad, Minn.-based Marvin. "And more and more companies are doing it. That is really cool. It's environmentally responsible and should be applauded."
Indeed, other Minnesota manufacturers are catching the "green" bug and bringing earth-friendly processes into their factories in a move that spares landfills and racks up millions in savings. Some use recycled ingredients instead of virgin. Others grow and burn their own heating fuel or use technology to slash hot water use; still others have perfected VOC (volatile organic compound)-free formulas that don't pollute the air.
State officials say the number of entrants into this green game swells each month and includes United Taconite, Northshore Mining, Bituminous Roadway in Inver Grove Heights, Midwest Asphalt, Hirshfield's Paints and Ecolab, among others.
Their approaches vary, but they all have an impact on wallets and the environment.
According to just-released state figures, Minnesota homes and businesses generated 6.2 million tons of municipal trash last year. They recycled 2.5 million tons of it (2 percent more than in 2005), which let businesses save $539 million in electricity costs and cut 6.4 million metric tons of carbon dioxide emissions.
"We still have 1.3 million tons of recyclable material that remains in the waste stream and it's worth $312 million," said Wayne Gjerde, recycling market development coordinator for the Minnesota Pollution Control Agency.
Companies such as Andersen and Marvin also save money that isn't tracked by the state because their sawdust waste never makes it into their cities' trash. That can cut back on hauling, landfill fees or material spending, Gjerde said.