SAPS: Energy independence down on the farm

Number 2 in the Sustainable Agricultural Practices Series.

Picture what it would be like to be energy independent and completely self-sustaining. Think also what it would mean if that paradigm was what everyone embraced, farmers included. It’s not out of the realm of possibility, you know.

Well, for Bill and Karla Chambers of Corvallis, Oregon, at their Stahlbush Island Farms, they’re already on board and this is exactly the way things on the farm have been for the two of them for quite some time now.

They invested $10 million (circa 2009) in an on-farm biogas plant that turns crop waste into electrical and thermal energy, according to Vegetable Growers News Managing Editor Matt Milkovich in “Vegetable, fruit waste can produce electricity,” in the Sept. 2009 Vegetable Growers News issue.

“When describing how the new biogas plant works, Bill compares it to a cow,” Milkovich wrote. “Whatever you feed to a cow, you can feed to a biogas plant; the end result for both is methane gas.

“Once collected, the corn silage, pumpkin waste and other organic material is ground up and placed in an anaerobic digester, where it turns into a soupy liquid. Bacteria convert the waste to volatile fatty acids, and a second set of bacteria converts those fatty acids to methane. The methane bubbles up through the liquid waste and is collected at the top of the digester, where it’s fed to an internal combustion engine that runs a generator to produce electricity, Bill said,” Milkovich added.

The VGN managing editor went on to explain that the process of anaerobic digestion cannot be shut down and the biogas facility must operate non-stop, so vegetable and fruit waste at Stahlbush Island Farms during the months of winter is stockpiled.

Milkovich explained further that when the plant is running full bore, it should generate nearly double the power needs of the farm. Any electricity not used, “will be sold back to the power grid, making the power company a customer rather than a vendor, [Bill Chambers] said.”

At that time when the biogas plant went online in June, according to Milkovich, Bill Chambers surmised that the 4,000-plus-acre farm could yield energy savings totaling $500,000 annually, the savings coming from not having to buy utility fed natural gas and electricity. Additional upsides to just such an investment include the labor saved from not needing to find ways to dispose of all of the crop waste. And, this added to the monetary savings and on-farm energy generation, by any measure, is a win-win-win absolutely.

One finale note: “Using waste to create energy also fit Bill and Karla’s goals of complete sustainability for their farm,” Milkovich offered. “And since the fruit and vegetable byproducts won’t be consumed anyway, they aren’t taking away from the food market to feed the energy market, Karla said.”

Published by Alan Kandel