Gas That Need Not Pass Unused
The sight of grain trucks rumbling from harvest fields has traditionally meant the restocking of our nation's pantry. But the destination of much of that grain has changed. Today, one of every six truckloads is burned as ethanol fuel.
Farmers have been recruited into the energy business with the promise of OPEC-style riches. They are plowing highly erodible acres retired a generation ago, all in the name of energy independence.
But why not instead encourage farmers to produce food first, with energy as a byproduct? Farm-based electricity generation is already at work in Europe, where livestock waste is being tapped as an energy source.
Georg Sturm farms in Germany's northern Bavaria, where he's fit a cutting-edge power cell into his family's medieval farm. Beyond his hand-swept, cobblestone courtyard stands a cinder-block building humming with electricity. Inside is a converted diesel generator powered by methane gas captured from fermenting manure. He sells a constant 250-kilovolt stream of electricity to the rural power grid, a profitable complement to his agricultural enterprises.
Germany leads Europe in on-farm generation of electricity from methane, or biogas, with 4,500 farms in the business of selling electricity at a price fixed by law.
"This simple system has led Germany to world leadership in wind, solar and biogas electricity generation," writes Paul Gipe for RenewableEnergyAccess.com. "Germany operates more wind generation, more solar systems and more biogas plants than any other country on earth."
Biogas is one form of "bioenergy," which now supplies just over 1 percent of Germany's electricity needs. The European Biomass Association wants to increase that to 4.4 percent by 2010.
In a land with a long tradition of self-sufficiency, biogas from farms and landfills promises Germans a reliable system not dependent on favorable weather. Unlike solar energy that shuts down on cloudy days or wind energy that quits when it's calm, biogas generators run nonstop because they're powered by animals that eat, drink and drop manure nonstop.
This small-scale electricity source passes the green test. And it's also green on the homeland security scale. Big centralized power plants make attractive terrorist targets, but small biogas generators scattered throughout the countryside don't.
Research at Cornell University estimates that methane from 2.5 million cattle could replace one 500-megawatt power plant. With nearly 100 million cattle in the United States, the potential for on-farm electricity generation is significant.
The energy from Georg's generator originates from crops grown within a mile of his farm and fed to 200 hogs and 50 slaughter bulls.
The cattle are born in small pastures but moved to well-ventilated barns after they're weaned, a centuries-old custom in northern Europe. Fresh straw is spread daily in the cattle pens, which slope to the center of a long shed. A conveyer chain drags along the concrete floor every two hours, scraping the soiled straw into a buried vat the size of a four-car garage.
Water used to rinse the hog barn floors is added to the vat, and mixer arms churn the slurry as it ferments. Naturally occurring bacteria break down the mixture, releasing methane that rises into an enormous plastic bag stuffed inside a silo. Air pressure feeds methane to the generator.
Sitting in Georg's 200-year-old home over fresh-baked pastries, I listened as he described the benefits of biogas generation. The farm produces high-quality beef and pork. Georg spreads the expended slurry on his fields, adding fertility without methane's disagreeable odor. That makes his village neighbors happy. He makes good income and supplies the surrounding area with power.
But he especially enjoys walking through his stone farmhouse in bare feet. Most German homes are heated sparingly, while Georg heats his house with hot water piped in from the generator's cooling system. It's so warm that the kitchen window is propped open despite the winter weather. He laughs about the waste of warm air seeping from his kitchen.
"Like in America," Georg says, he's got energy to burn.
Chris Frasier visited Georg Sturm's farm in 2007, 20 years after working as an exchange student on a neighboring farm. Frasier ranches with his family near Limon, Colo. He wrote this comment for the Land Institute's Prairie Writers Circle, Salina, Kan.