The word Wisconsin brings up visions of beer, cheese, and the Green Bay Packers. Although the football team is powerful, Wisconsin’s cheese industry may win the waste-to-energy Super Bowl.
During the cheese making process, milk solids are separated from liquid whey. The solids become cheese, and the whey is used in various food products. After the cheese is rinsed, the rinse water includes traces of whey and milk. This rinse water can be used as a fertilizer, but during the winter months when the ground is frozen, the water would run off into streams, rivers, and lakes, causing pollution.
Entrepreneur and former dairy farmer Tom Ludy decided to tackle this problem. His company, GreenWhey Energy, is building a plant that converts this waste water into solid fertilizer and methane gas. The methane is burned to produce electricity.
The “waste” heat from the generators heats the anaerobic digester and the plant itself. The solid fertilizer is sold to farmers. The nearly clean waste water from this process goes to a municipal water treatment plant and is then discharged into the water supply. In the future, Ludy hopes to process the water at the GreenWhey facility rather than shipping it to a treatment plant.
The GreenWhey plant is under construction. They expect to go online in June of 2013.
The GreenWhey facility will be one of the largest of its kind, generating 3.2 megawatts of electricity - enough to power 3000 homes. While that doesn't seem like a lot of power, GreenWhey's web site states, "GreenWhey Energy is first and foremost a wastewater treatment facility. We’ll charge a fee to manage waste streams for dairy and food processing plants. The income we’ll generate from the production of electricity, heat, and fertilizer sales is like icing on the cake."
The old saying “one man’s trash is another man’s treasure” holds true, as GreenWhey will make money on both ends of the process. Not only do they not have to pay for their raw material, GreenWhey gets paid to take it off the hands of cheese factories. After processing, GreenWhey sells the solid fertilizer to farmers and sells the electricity to the power company. Whey to go!
Images courtesy of GreenWhey Energy
For more about the benefits of anaerobic digestion, watch this video from Anaerobic-Digestion.com: