A Load of Manure
Livestock farmer and environmental lawyer Nicolette Hahn Niman writes in the NY Times about the false promise of using manure as a power source.
The idea sounds appealing, but power from manure turns out to be a poor source of energy. Unlike solar or wind, it can create more environmental problems than it solves. And it ends up subsidizing large agribusiness. That's why energy from manure should really be considered a form of "brown power."Niman points out that methane digesters and other ways of getting energy from manure approach efficiency only in places where huge amounts of manure are available--CAFO's (or maybe the White House press room). And even in these cases, the process only becomes profitable when government subsidies are introduced--which is what aWol has been babbling about lately. Hahn Himan continues:
And those subsidies tend to help factory farms. Traditional farms, which usually both grow plants and raise animals, recycle manure as organic fertilizer and thus bear the full cost of handling their waste. But large livestock operations can't do that. They put their manure — and there is a great deal of it — in huge piles or storage pools that often leak into nearby streams and ground water and exude stenches that make life miserable for neighbors. For them, manure isn't valuable fertilizer but a vexing disposal problem.
The stampede for power from manure gives these huge livestock operations a subsidized way to deal with this problem — and even gives them an incentive to expand. An article about methane digesters in The Des Moines Register quoted a farmer saying that doubling his dairy herd allowed him to justify the expense of a digester. This could well be a typical response, with manure power projects everywhere resulting in still larger herds and flocks.
But as the United Nations Food and Agriculture Organization noted last month, concentrated livestock operations threaten the environment and human health in a way that traditional farms do not. It is increasingly clear that traditional, smaller-scale farming is better than factory farms for people, animals and the environment.
Even manure power projects' immediate environmental benefits are dubious. Digesters, for example, don't make the manure disappear; instead, a manure slurry (which is sometimes larger than the original volume of manure) is left over and still has to be stored somewhere. Moreover, the slurry contains most of manure's original pollutants, researchers note. In other words, what comes out of a digester may be a bigger problem than what went in.
Methane digesters also fail to abate most environmental damage caused by concentrated animal operations, according to the Sierra Club. Farms with digesters still generally use large manure storage ponds, the main source of pollution problems. Incinerators, meanwhile, destroy the valuable components of manure and raise the specter of air emissions. While it's a nuisance on factory farms, manure as it is used on traditional farms greatly benefits soil fertility and tilth, increasing water-holding capacity, reducing wind erosion, improving aeration and promoting beneficial organisms. But many of these benefits are lost in burning. "Incineration destroys the nitrogen and organic material content of manure," reports the Institute for Local Self-Reliance. The institute has calculated that "an electricity plant that burns 500,000 tons of manure in effect destroys $3 million in nitrogen."
Using manure as power sounds like a good idea, but it's not. The energy that can be generated from manure is not worth the expense. And by lowering industrial animal operations' cost of production, subsidizing manure power pushes family farms further toward the brink of extinction. Our money would be better spent investing in truly sustainable, sensible ways of producing energy and food.