At one end of High Island Dairy in southern Minnesota's Nicollet County, Jersey cows are guided one at a time into 72 stalls on a rotating platform where they are milked in a matter of minutes. The 3,000 cows at the dairy go through the process three times daily, and shiny tanker trucks speed the quick-chilled milk to a cheese processing plant in Le Sueur 9 miles away.
The less savory part of the business is the 80,000 pounds of manure the cows also produce each day, which is vacuumed, scraped and piped into a pair of 1.1 million gallon covered tanks. Plastic domes above the tanks bulge with methane gas produced inside as microbes digest the manure in a sealed environment.
"The dome is a tent that holds the gas in the head space," said Mitch Davis, managing partner of Davis Family Dairies, High Island's owner.
The method of manure treatment, called anaerobic digestion or methane digestion, benefits the environment, Davis said, because it produces renewable energy that can be captured instead of released to the atmosphere and then burned to produce heat and electricity.
It's also one strategy the Obama administration has focused on as a way to reduce methane, a powerful contributor to global warming gases.
"Pound for pound," the U.S. Department of Agriculture (USDA) points out, "the impact of methane on climate change is 20 times greater than carbon dioxide."
In March 2014, the White House introduced a "Biogas Roadmap," a voluntary poop to power program that it bills as a way to help the U.S. dairy industry reduce its greenhouse gas emissions. In 2008, the industry set a voluntary goal of cutting those emissions by 25 percent by 2020.
Problem is, turning manure into methane-fueled heat and electricity has yet to catch on widely in Minnesota or around the country. USDA officials, who held the first meeting of a biogas working group in late July, liken the situation to other forms of renewable energy, such as solar power, which took years to reach a critical mass that made them viable.
The number of dairy farmers applying to a USDA program that funds renewable energy systems more than tripled in the past year. Many of those grants and loans have been approved. But little money has been distributed.
The biogas industry "is still under development," said Sam Rikkers, assistant administrator of the USDA's Rural Business-Cooperative Service.
Some experts wonder if it will ever blossom.
"In recent years, lower natural gas prices and more solar power sales have worked against anaerobic power," said Fritz Ebinger, rural power development manager at the University of Minnesota Extension. "If the Obama administration wants to see poop to power, there's going to have to be an energy subsidy."
Challenging economics
Finding an economically viable route on the Biogas Roadmap has been a struggle, acknowledged Chad Frahm, vice president for sustainability at the Innovation Center for U.S. Dairy.
"When you look at [reducing] methane emissions, we've found successful biogas technologies," Frahm told the Star Tribune. "The challenges are electricity prices and how to create additional value for byproducts."
Besides creating methane for electrical generation, manure has been used to create a biomass product that can used as bedding for cows. Byproducts of manure have been turned into fertilizer, Frahm said.
There is also a way to process manure into natural gas that can be used to power vehicles or to introduce into pipelines, Rikkers said.
The Biogas Roadmap ultimately envisions the deployment of more than 11,000 biogas systems nationwide. It talks of energy production that powers 3 million homes and cuts methane emissions by 4 million to 54 million metric tons by 2030. There now are just 239 biogas livestock systems in the U.S. They produce enough energy to power just 70,000 homes.
Utilities "aren't geared to biogas," Rikkers noted. "We believe that promoting the industry can lead to economies of scale and cost-effective technologies. Then, power grids will better recognize the opportunity."
At the Davis family's High Island Dairy, which opened in late 2013, theory meets practice. The methane gas is piped to five engines and burned to produce heat and more than 90 percent of the electricity the dairy consumes. But the power is not sold on the grid. "Our economic benefit is all internal," Davis said.
In addition to saving on electricity, the digester also reduces odor, produces pathogen-free fiber bedding for cows and delivers a high quality manure to be injected into cropland. It also helps the company's image, said Davis, whose family also owns Northern Plains Dairy, New Sweden Dairy and Granby Calf Ranch, as well as Cambria, the maker of quartz countertops, and Sun Country Airlines.
Another chore
As the White House and the dairy industry tout their potential, methane digesters only operate at a handful of Minnesota dairies. Even fewer sell the resulting electricity for commercial consumption.
The pioneer of the group, Dennis Haubenschild, built the first methane digester on a Minnesota dairy in 1999 at his farm near Princeton, and has been producing hot water and electricity ever since and selling the power to his local co-op.
Initially Haubenschild had 400 cows, and produced the electricity for his farm and about 80 homes. Now his herd is about 1,000, and the extra power probably supplies about 30 homes, he said.
Another challenge is that dealing with the biology of microbes in a digester can be tricky, he said, and may take months to fine tune — requiring more expertise and time than many producers can afford.
"It's like you've got another chore, and you have another animal on the farm," he said referring to the living microbes. "You can't treat it as a machine that you can turn on and off. It's a living thing and it's got to be taken care of just like your calves or your cows or anything else."
Despite those obstacles, Haubenschild said digesters will eventually become more feasible and widespread on dairies and elsewhere. "Not only can we be supplying food, we could also be supplying energy," he said.
"It's one of the tools that we have in our toolbox that everybody should be using. It's just that it's not really needed right now."
That is not how environmentalists in the Obama administration see it. They are "leveraging" more than $10 million in research funding to find ways to make the approach economically viable. They're also looking for ways to attract more investment. And perhaps most important, they are working "to overcome barriers to integrating biogas into electricity and renewable gas markets."
This last piece is critical, said the U's Ebinger. Right now utilities won't pay enough for methane-generated power for farmers to reach a break-even point, much less make money.
Until that happens, potholes in the road to biogas sustainability may be too big to maneuver around.
At the very least, the dairy industry's voluntary goal of 25 percent greenhouse gas reduction by 2020 remains elusive.
"We are committed to that," said the dairy innovation center's Frahm. "It's too early to tell at this point if we'll make it."
Tom Meersman 612-673-7388 Jim Spencer • 202-383-6123
