Remember that old saying, when life hands you lemons, make lemonade? That’s exactly what dairy farmers and researchers around the country are doing as they hunt for ways to monetize poop. Entrepreneurial dairy farmers, with an assist from anaerobic digesters, are finding ways to transform manure into money while also solving some climate concerns. Manure may not yet be creating more profits than the milk the dairy cows produce, but right it’s certainly an additional revenue stream for those willing to scale up their manure management.
It starts with a digester, which happened to be invented in 1859 at a leper colony in India with the goal to take the waste and use it for both lighting and cooking. In the late 19th century, the concept migrated to England, where human waste was used to power street lamps. Basically, methane gas which can be used in most places natural gas can, is extracted, then microbes and bacteria do the transformational work. No one questions the viability of the technology, but for a long time, it remained something of a curiosity, probably because of widespread reluctance to deal with manure at all. But then two things happened:
1. Post-WW II, technological innovation allowed manufacturers to produce and make the machines significantly larger. In fact, the dimensions of a digester at an 800 cow dairy can measure 72 feet wide by 96 feet long by 16 feet deep, in a U-shaped configuration holding almost 800,000 gallons.
2. This set the stage for the second development, dairy farms increasing size as farmers seek economies of scale. Keep in mind, when a farmer milked a few dozen cows as was customary 50 years ago, it was easy to put the manure to use on the farm, but today’s farms often involve thousands of cows. Hence a lot more manure to deal with.
Currently, there are 207 anaerobic digesters operating on America’s 40,000 dairy farms, many of which were installed between 2006-13 in the Midwest and Northeast, thanks in a big part to the Farm Bill funding through USDA’s Rural Energy for America Program. But in the last five years, most new dairy digesters have been placed in California. I know of just a handful of new ones here in the Midwest. I’m told the cost of a digester for a typical dairy farm, meaning one with a few hundred cows, is around $1 million, but as you step up to a megafarm with +7,500 head, the cost can have a rather large multiplier and vary greatly.
Operational in the next month, the Butterfield Dairy in Buckeye, Arizona, will have 55,000 daily tons of manure from some 25,000 cows that will get transformed into 3 million therms per year, the equivalent of taking 3,500 cars off the roads, and across the country, many hundreds of similar energy-producing operations are springing up as producers look for ways to minimize methane’s negative environmental impacts and also for comparatively clean, renewable energy sources. It appears that cow manure checks all the boxes as part of the solution.
Interestingly, as attention to cutting emissions grows, there is a policy push at both the state and federal levels toward supporting animal farm biogas projects, not only with subsidies to build but also including them in carbon offset markets. It’s worth noting, in the past, methane digesters have been installed on smaller dairy farms to power those farms or in local closed-loop systems. But as momentum for cleaner energy and emissions reductions in animal agriculture has grown, Big Ag companies have joined forces with gas companies to scale up the projects and connect them to natural gas pipelines, something that environmentalists say is a false climate solution.
I should mention, environmental and animal welfare advocates believe that the methane wouldn’t be here in the first place if not for the new production levels and they also claim that the government supports in the form of carbon markets and tax breaks will tilt the playing field in favor of the largest industrial operations and support larger, and more concentrated CAFOs, which their camp believes negatively impacts people and the environment in other ways. Just stating their side of the argument.
The debates between environmentalists and animal welfare versus the large scale production of food won’t be going away anytime soon, so I suspect the key is to show the powers that be the viability and multi usability of waste from livestock operations starting with the methane capture, to the fertilizer, dry bedding, and clean water productions as well… All of which will help cut back on carbon emissions in the process.
Looking ahead, I have to imagine the use of anaerobic digestion for poultry and beef operations will grow as new technologies enter the space, hopefully bringing down the price and making them more accessible to all operators.
