OPINION | March 4, 2022
Op-Ed Contributor: A Load of Manure
By NICOLETTE HAHN NIMAN, Bolinas, Calif.
Unlike solar or wind, power from manure can create more environmental
problems than it solves and is a poor source of energy.
TALK of reducing
our dependence on foreign oil through alternative energy sources
like biomass is
everywhere these days — even on
our president's lips. As a livestock farmer and environmental lawyer,
I've paid particular attention to discussion about using manure as "green
power." 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."
Manure is used mainly in methane digesters, incinerators and certain
biodiesel plants. Digesters, often at dairy farms, liquefy manure,
then put it in large tanks with anaerobic bacteria. As the liquid decays,
the bacteria produce methane, which is purified and used like natural
gas. Incinerators generate power by burning animal waste, usually from
poultry. Biodiesel involves creating a gas from manure, then combining
it with oil from animal fat or plants (often soybeans or corn).
Government officials tout such projects as energy generation that
benefits both nature and agriculture, and are pouring public funds
into them. Few seem to question whether the projects make economic
or environmental sense. And there are plenty of questions that need
to be addressed. For starters, manure simply does not contain enough
energy to produce cost-effective power. Studies show that manure power
projects are probably not viable without large public subsidies and
are likely to remain so. An analysis by researchers at the University
of Minnesota's Applied Economics Department found that methane digesters
are dependent on big subsidies to break even. Electrical rates would
have to double to pay the full cost of digesters, says Jeff Lorimor,
an Iowa State University agricultural engineering professor. Electricity
from manure-burning incinerators is also much more expensive than other
power, requiring federal and state subsidies to make it competitive
with other sources, according to the Institute for Local Self-Reliance.
Part of the problem is that the digesters, incinerators and biodiesel
plants are expensive to build and run. Cost and technical complexity
make these manure power projects more economical when done on an industrial
scale, with operations that produce vast quantities of manure. It's
telling that one of the first major manure biodiesel plants in the
United States will use the millions of pounds of waste produced by
the 500,000 pigs at a Smithfield Foods operation in Utah.
But even the largest projects require significant public money for
construction and operation. This has also been Europe's experience
with manure power projects.
And those subsidies
tend to help factory farms. Traditional farms, which usually both
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
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.
also fail to abate most environmental damage caused by concentrated
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."
The fossil fuels involved in hauling manure must also be considered.
Incinerators, especially, are centralized and bring waste from farms
for miles around, and then the resulting ash must be transported to
a disposal site.
Bush's statement that biodiesel "is one of
our nation's most promising alternative fuel sources," making
biodiesel from manure is also unlikely to be an environmental gain.
Burning biodiesel may increase a greenhouse gas, nitrogen oxide, according
to the Energy Department. And the full environmental costs of biodiesel
fuel include soil erosion and water pollution caused by growing the
soybeans and corn used. These crops are now the leading cause of both
nitrogen water pollution in the United States and soil erosion.
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.
Nicolette Hahn Niman is a lawyer and cattle rancher.