NORMAN — The notion of spinning straw into gold is a fairy tale staple, thanks to accounts of the mischievous dwarf Rumpelstiltskin.
Jerry Bingold, director of renewable energy for the Innovation Center of U.S. Dairy, is touting a modern-day version of that story, with cow manure serving as a source of renewable energy.
Bingold said anaerobic digesters — which are like large covered swimming pools underground filled with bacteria — can capture the methane in cow manure, allowing the dairy industry to reduce its carbon footprint and providing farmers with another source of revenue. “This was a milestone,” he said. “It's actually given a road map to other industries.”
Bingold spoke to about 150 people Tuesday at Touchstone Energy Cooperatives' 2011 Emerging Technology Conference in Norman.
He described the process of turning poop into power, while spotlighting examples of the technology.
Bingold said the technology is best suited to large commercial farms where cows are fed in a line and remain in their stalls. The cement floors in such farms make it easier to collect manure twice a day, he said, showing a picture of pea green slurry that results when manure is washed into the digester.
“From there, we get green power,” he said, drawing chuckles and groans from the audience.
Bingold said bacteria in the digester, buried 16 feet underground, convert the manure into methane in about 21 days. Methane, the main component of natural gas, can be used to generate electricity or fuel vehicles.
The process also yields garden fiber, which potentially could be marketed like peat moss, and effluent high in potassium, nitrogen and phosphorus that can be used as fertilizer, he said.
Bingold said the addition of food waste, which many retailers pay to get rid of, can increase methane production in digesters by 200 percent.
“We're creating an industry here,” he said.
Bingold said he expects biogas, which can be harvested from beef or swine operations, to be developed by third-party companies, as with wind and solar power.
The U.S. has about 2,200 dairies with more than 1,000 cows. About 60 percent are candidates for digesters. He said technology gives electric cooperatives a chance to work with farmers to get cheaper fuel.
Mark Faulkenberry, manager of marketing and communications for Western Farmers Electric Cooperative, said biogas can be part of a utility company's baseload power generation, unlike other renewables.
Bingold, who hopes to have 1,300 digesters on U.S. dairy farms by 2020, said there is a lot to work with, as each cow produces about 150 pounds of manure a day.
This was a milestone. It's actually given a road map to other industries.”