The Amazing Animal That Puts Food on Your Plate and Powers Your Home

Cow power is ramping up as farmers generate clean energy from manure—and make money supplying electricity to utilities.

(Photo: David G. Kelly)

Jan 16, 2015· 3 MIN READ
Melanie Haiken is a San Francisco Bay Area–based health, science, and travel writer who contributes regularly to and numerous national magazines.

The next time you open your refrigerator for a glass of milk, you might thank a cow for supplying not just your drink but also the electricity powering the fridge light.

Move over, solar; move over, wind: The next big renewable energy source might be…cows. Or, more specifically, cow manure. (Not to mention hog manure, chicken manure—you get the picture.)

Projects that use animal waste from dairies, farms, and feedlots—aka “cow power”—to generate low-emission biogas are coming into their own as an economically viable renewable energy source, thanks to new federal and state incentive programs making them more accessible to cash-strapped farmers.

In August, the government unveiled the Biogas Opportunities Roadmap, which outlines a strategy for getting dairies across the country on board with biogas, allocating more than $10 million in research funding and project costs.

“It seems like for a long, long time we’ve been hearing that the era of agricultural biogas is just over the horizon, and that horizon is finally here,” said Diane Bailey, a senior scientist with the Natural Resources Defense Council. “There are so many real benefits to biogas, but the barrier has been the up-front costs to build the systems. Now we’re seeing real dollars, as well as a public push to get farmers on board.”

Capturing biogas from farms is a triple—or even quadruple—win, says Bailey. First, by capturing methane released by manure, biogas systems prevent it from reaching the atmosphere as a potent greenhouse gas. With methane currently accounting for almost 10 percent of greenhouse gas emissions, that’s a significant goal on its own.

Next, anaerobic biodigesters convert that methane into natural gas, which can be used to generate electricity or can be cleaned up and funneled into gas pipelines. Then there are the issues of air and water pollution caused by animal wastes—biodigesters solve those problems too. Last, consider that biogas replaces fossil fuels, reducing consumption.

But wait, there’s more: Many farmers are taking advantage of the solid waste left behind, selling it as a rich, natural fertilizer. “That’s an incredible opportunity to replace a lot of damaging synthetic fertilizers,” Bailey said.

Many biodigester systems are closed loops, powering farms and farm equipment but without connection to the power grid. But in a growing trend, utility companies are tapping farm-produced biogas and selling it to customers.

One motivator: mandates now in place in 30 states that require power companies to produce a certain percentage of their electricity from renewable energy sources. Farms and ranches that become certified as renewable energy generators earn energy credits for every unit of electricity they produce, which they can sell—along with the electricity itself —to local utilities.

In Vermont, an early leader in agricultural biogas, customers of Green Mountain Power can now check a box to become Cow Power consumers and use electricity generated by 12 local dairy farms. A premium of four cents per kilowatt hour goes straight back to the farmers, helping local farms stay in business.

Agricultural biogas, though, is still stuck in the slow lane in most parts of the country. The most recent government figures from 2012 identified just 186 digesters operating in commercial farming in the U.S. Not a lot, considering the potential.

Were 8,200 dairy and hog farms that could produce biogas to take action, the U.S. Environmental Protection Agency estimates the potential energy gain at more than 13 million megawatt hours a year. That would keep1.8 million tons of methane from entering the atmosphere—the equivalent of taking 6.5 million cars off the road, according to NRDC estimates.

Change is coming.

California’s Department of Food and Agriculture this week announced the Dairy Digester Research and Development Program, which commits about $11 million for dairy farmers who apply for assistance to install biodigesters.

The idea is to boost the pace of agricultural biogas development in the state by providing farmers with the technology needed to get a biodigester up and running.

“We’ve had some very energetic and forward-thinking farmers who’ve gone out on their own and learned how to do this,” said CDFA spokesman Jay Van Rein. “But now there’s much more expertise to go around, and we can pair farmers with those who already have the knowledge and experience. That’s how the future of this technology is shaping up.”

Federal money is also coming to farmers from agencies such as REAP (Rural Energy for Farms Funding), which just allocated $80 million to biogas development and will cover up to 25 percent of project launch costs.

And that’s just one source of money available. Farmers can cobble together numerous funding sources. As Bailey put it: “Biogas presents such an enormous untapped opportunity, and all we needed was the funding to tip it over the edge. Now that we have it, I think we’ll finally see those biogas systems getting built.”

It may not be possible to spin straw into gold, but manure could be our next source of energy riches.