Cheese Wastewater To Power 3,000 Homes
By Sara Jerome
Cheese wastewater appears to have a surprising benefit: It can generate electricity.
Wisconsin is taking the lead on this unusual idea. "As the country's largest producer of cheese, Wisconsin is also the country's largest producer of cheese waste. But why think of that as a bad thing? In the hands of some enterprising Wisconsinites, what was once wastewater is now electricity," Gizmodo reported.
St. Croix 360 explained how Wisconsin is putting cheese wastewater to such a powerful use. "GreenWhey Energy, a new company in Turtle Lake, is taking the waste and as an initial step removing much of the harmful material," the report said.
"Using technology developed by St. Paul-based Ecolab, GreenWhey feeds the waste to a 4-million-gallon tank full of microbes. As they consume the nutrients, the digesters expel methane and other gas. That gas is used to power generators which can produce enough electricity to power about 3,000 homes," the report said.
GreenWhey works with dairies to get ahold of its wastewater, according to WXOW. The water comes in by way of truck and pipeline.
"Wastewater is then pumped into five holding tanks. It then goes into a larger equalization tank where additives are mixed in to create the proper pH levels. From there it heads to the digesters, which turn it into methane gas. It's then pumped into two huge engines, which create electricity. The only by-products are water, bio-solids that can be used as fertilizer, and clean, green energy," the report said.
The wastewater, which contained nitrogen and phosphorous, was problematic because it fed algae when it was released back into environment, 360 said. It also depleted oxygen in the air.
Why is this innovation popping up now? Because of recent regulations.
"For years, the milky rinse water was spread on farmland as a low-grade fertilizer, but the practice was curtailed in the face of more stringent environmental regulations to limit runoff pollution, especially in the winter months when spraying on frozen ground was outlawed," NBC News reported.
"We knew we had a problem because we can’t stop the ground from freezing," Tom Ludy, president and co-owner of GreenWhey, told NBC News, noting that “Dairy plants run 7 days a week, 24 hours a day and cows produce milk on the same schedule.”
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Image credit: "Cheese," © 2011 Pieter v Marion, used under a Attribution-ShareAlike 2.0 Generic license: http://creativecommons.org/licenses/by-sa/2.0/