Methane: From Cows: The Pulse of the Planet daily radio program offers free legal online mp3 downloads, exploring the world of sound in nature, culture and science, with audio adventures, world music, extraordinary sound portraits, science diaries, and nature ring-tones; an amazing sonic experience.

Airdate: Apr 26, 2001
Scientist: Roger Decker (see also actions for other interviewee)

Methane: From Cows

Methane: From Cows
Cow manure is now being used as a source for electricity.


ambience: mooing, milking machine

We're on a dairy farm in Iowa, where the cows are particularly well-cared for. And they certainly deserve to be, because these cows are not only providing milk - they're helping to generate electricity. I'm Jim Metzner, and this is the Pulse of the Planet.

Roger Decker is owner of Top Deck Farm.

"We’ve been farming for forty years. We have a herd of Holstein dairy cows that we milk in a free stall barn in a parlor system. We’ve got these comfort stalls, we call them. If you walk up on there, it's just like walking on a carpet in your house. It feels good on your feet, and they have a feed alley, twelve foot from where they lay."

The reason the Holsteins here are living in such comfort is that in addition to milk, they're also providing methane gas which will later be used to generate electricity. The cows have to be confined so that their manure can be collected.

"The manure that comes through the cow is scraped on alleys down into a system that pumps the manure into the digester, and there'll be a heat exchanger in there and we actually heat this manure before it goes into the tank and it forms a gas at the top of the tank, and that is the methane."

The manure is contained and burned inside the digester before it can reach the air. This addresses one of the negative side effects of producing methane from manure - the distinctive odor.

"This is a win-win situation for neighbors for one thing. By running it through digester, we’re going to really cut the smell down which is kind of rude to neighbors."

Roger Decker and his family are the first farmers in Iowa to sell methane to a utility company.

Pulse of the Planet is presented by the National Science Foundation. I'm Jim Metzner.