It’s Poo Power: How Dairy Cows Could Provide the Electricity of the Future

Posted by on Oct 9, 2017
It’s Poo Power: How Dairy Cows Could Provide the Electricity of the Future

They call it ‘cow power.’ A San Francisco-based company, Sustainable Conservation, wants to use the methane produced from cow manure to provide electricity for mass consumption.

California is home to nearly 1,750 California dairy farms and 1.79 million milk cows, and as wonderful as this burgeoning California industry may be, these cows – and others – contribute approximately 14.5 percent of today’s total, human-induced greenhouse gas. Cows and other farm animal manure – and manure’s own, living bacteria ecosystem – produce copious amounts of methane, and this greenhouse gas is, as we now know, a major contributor to global warming (nearly thirty times more potent as a heat-trapping greenhouse gas than the normally blamed global warming culprit, carbon dioxide). Sustainable Conservation leads the movement to harvest this so-called ‘cow power,’ this methane gas, and convert it to clean energy.

But how? Methane is released from cow manure when bacteria in the cow faeces begin to break down the biodegradable materials in the manure. At Sustainable Conservation’s methane-harvesting farms (which are actually local-area, California, large-scale dairy farms), freshly-deposited (shall we say, freshly pooed?) manure is swept away from feed stalls in a steady stream of wastewater from the farm’s cheese plant. From there, it is transported to a manure sifter that separates solids from liquids, and the remaining manure water is transported to large, billowy tents where the bacteria can begin work on the manure water in an anaerobic environment. The remaining solid faeces, now which look like nothing more than dark, hay chaff rich with nutrients, make their way to a pile outside the farm to later be picked up as plant fertilizer. Meanwhile, as the bacteria work their magic on the manure water, complex carbohydrates in the waste are converted to methane gas. The gas is trapped by the billowing tents that trapped the aforementioned manure water beneath it, the gas is transported to various, specialized generators, and the methane is directly transformed into useable, workable electricity. In turn, the biomethane powers the company’s and farm’s cheese manufacturing and packaging factory. The methane from the farm in question’s own 16,000 cows provides as much as eighty percent of the plant’s electrical needs.

So what? For one, having eighty percent of the cheese plant’s electricity provided by their own cows saves the company, Joseph Farms, nearly $1,500 a day in electric costs and spares them 300,000 gallons of propane a year. Yes, the whole methane digester system did cost the farm two million dollars to start up, but with tax breaks, government grants, and the extraordinary daily savings in energy costs, the dairy making business serves as a model citizen for Sustainable Conservation’s revolutionary system.

But until traditional energy companies agree to buy back the energy produced by the methane digesters, Sustainable Conservation’s system remains a novel, inventive foray into the future of energy studies, sustainability, and another well-aimed attempt to slow down the process of global warming.

Perhaps it isn’t all as dire and sour (milk) sounding as all that? There has to be a silver lining to this poo-laden enterprise. To start, Sustainable Conservation’s project challenges us to forge a renewed intellectual connection between the food we consume and the things we produce, i.e. the waste we create. It asks us to consider the after effects of every item we consume, every bit we eat, every object we create. The glass of milk is never just a glass of milk. And the glass of milk is never just a foodstuff we consume. The before and after effects of the glass of milk sit with us. They resonate with us. Milk’s story does not begin and end at consumption. Instead, Sustainable Conservation and their methane digesters make us think of the farmer, the cow, cow life, cow waste, cow death. And it is at this linchpin of cow waste that we find ourselves. What must we create to get cow milk or cheese? What do we do with these unsavory, side creations? What do we do with the waste?

The answer, at least within this limited context and subject of energy, is manure – more specifically the methane produced from that manure. Thanks to fascinating bacterial decomposition of mere, biologic, animal waste, methane can be harvested and transformed into biofuels in forms usable both as a substitute for natural gas and as an automotive fuel. Conservation Sustainability’s groundbreaking work seems like a positive start to an innovative alternative energy source. But why, in 2017, have we still not heard much about this renewable energy plan?

The explanation is simple: industry restrictions. As summed up by Ken Krich, Don Augenstein, J.P. Batmale, et al., the major factors limiting a so-called energy ‘manure manifesto” follow:

  • “Producing biomethane from dairy manure is not technically difficult, but it is challenging to produce it cost competitively with natural gas on the relatively small scale of a dairy.
  • Dairies can produce more biomethane than they can use. A successful project must identify an off farm use, and provide a means to transport and store the fuel.
  • There are institutional and regulatory barriers to transporting biomethane through the natural gas pipeline which will be difficult to overcome. Alternatively, it can be transported by dedicated pipeline or truck. 
  • Current Federal and State [sic] programs provide little support for biomethane.
  • The estimated cost of producing biogas and upgrading it to biomethane on farm can be competitive with the price the dairy would pay for natural gas. Added to the production cost is the cost of transportation and storage.
  • Electrical generation from biogas is more cost effective than upgrading the biogas to biomethane, but current regulations make it difficult for the farmer to realize the economic value of the electricity he/she generates.
  • [Although] Biomethane is a proven vehicle fuel, [few vehicles are made to run on it]. [However, consider that] Sweden has 20 plants producing biomethane and runs 2,300 vehicles, mostly buses on it.”

Where does this leave us? Well, I can tell you one thing… It leaves me, an Indiana-bred farm kid turned PhD candidate, wanting to travel to California to learn as much as I can about biofuel and methane digesters. The future could be in poo. Plus, cows are pretty cool, too.



“California Milk, Dairy, Cheese, Ice Cream Facts.” See California. Accessed October 2, 2017.

Chea, Terence. “Moo! Cows Targeted in Global Warming Battle.” Us News & World Report. November 29, 2016. Accessed October 2, 2017.

Joseph Farms. Accessed October 1, 2017.

Krich, Ken. Don Augenstein, J.P. Batmale, John Benemann, Brad Rutledge, and Dara Salour. Biomethane from Dairy Waste A Sourcebook for the Production and Use of Renewable

Natural Gas in California. 2005. Accessed Oct. 1, 2017.

Miller, Amy and Joan Johnson. “From Waste To Watts: Biofuel Bonanza.” Quest. July 10, 2007.

Princeton University. “A More Potent Greenhouse Gas than Carbon Dioxide, Methane Emissions Will Leap as Earth Warms.” Science Daily. March 27, 2014. Accessed October 2, 2017.

Sustainable Conservation. “Cow Power.” Accessed October 1, 2017.