Tapping the Latent Power in What's Left Around the Barnyard
"We're not taking any risk, the reduction in odors is huge, and we're powering 600 homes with 900 cows," he said. "You've got to admit, that's pretty efficient."
The deals are struck in different ways. In most cases, farmers buy digesters and either use the gas themselves, sell it to a utility, or use it to power a generator that feeds electricity to the utility's grid. In another model, the manufacturer owns the digester and sells the gas. In those cases the farmers provide the manure and the land, and get the fertilizer, bedding and a cut of revenues from sales of gas. Last year, for example, Hunter Haven Farms in Pearl City, Ill., paid $960,000 — half of it subsidized by state and federal grants — for a GHD digester that processes waste from 600 dairy cows. Hunter Haven then pipes its methane into a generator, and sells the resulting electricity to Commonwealth Edison for 3.5 cents per kilowatt hour.
