When you think of what federal economic stimulus money has paid for, the first things that come to mind might be highway paving, energy retrofits or high–speed trains. Now here’s one of the most unconventional stimulus projects we’ve heard of. An institute at Western Washington University is getting half a million dollars to examine how to convert cow poop into horsepower.
Five years ago, dairy farmer Darryl Vander Haak flipped the switch on the first poop–to–power generator in Washington State. Officially, the facility near Lynden, Washington is known as a methane digester. Manure from around a 1000 cows goes in one end. Then controlled decomposition yields methane gas. It’s burned like natural gas in an electric generator.
The rub is, electricity sales haven’t been very profitable, or profitable at all says dairyman Vander Haak.
Vander Haak: “We’re looking for alternative ways. The Northwest has too much hydropower to compete with. It would be easier to compete with the gas companies, I guess.”
That’s why Vander Haak was open minded when the director of the Vehicle Research Institute at Western Washington University came calling from down the road in Bellingham. Eric Leonhardt says he’s long had his eye on the dairy herd as a source of transportation fuel.
Leonhardt: “The problem is when the gas comes off the digester, it has not only methane in it — 60 percent — it also has carbon dioxide — forty percent, roughly. And it has a trace of hydrogen sulfide.”
Leonhardt says the challenge is to remove those engine–wrecking impurities cost–effectively. Other than that, powering vehicles with natural gas is not new. Generating the fuel from renewable sources has been done before too, for example at landfills. The U.S. Department of Energy gave the $500,000 grant to improve the fuel refining process and then demonstrate whether biogas could be cost–competitive. At lot depends on the price of fossil fuels.
Leonhardt: “At $6 a gallon, the payoff period isn’t very long.”
Banse: “So $6 a gallon for petroleum fuel?”
Leonhardt: “Yes. If you start at $3 a gallon, it’s a push. It is right on the edge of being possible.”
This spring, the Vehicle Research Institute plans to retrofit a donated airporter shuttle bus. It will take a few months of road testing to confirm Leonhardt’s cost estimates. The researcher has already calculated that the cows from just two large dairies could fuel all the public buses in his home of Whatcom County.
I’m Tom Banse in Bellingham, Washington.
Tom Banse, KUOW – http://kuow.org/program.php?id=19447