sustainablog: Poop and Pee to Power

The animal wastes keep coming, and new ideas about converting them to energy are right behind them:

From the Milwaukee Journal Sentinal via TriplePundit, Wisconsinites (or, at least, Wisconsin dairy farmers) are in the poop-to-power vanguard. This article focuses on the use of anaerobic digesters to convert massive amounts of cow manure into power:

The manure management side of farming is far less smelly and far more profitable when the animal waste is converted into a power source.

Such a biomass process is up and running at farms across Wisconsin and other states. Although the basic technology isn't new, it's generating attention for a local company, GHD Inc.

Company owner Steve Dvorak has run a farm implement dealership for 27 years. The farm boy turned engineer kept hearing farmers complain about manure management, and ended up developing his own line of anaerobic digesters, or waste-to-energy processors, in a complex system born of the simplicity of nature's call.

His business, with 11 employees, sells such systems around the state, across the country and now overseas.

In an anaerobic digester, cow manure is funneled in 24-inch underground pipes to long underground caverns, about the length of a football field.

A generator is used to heat the manure to 100 degrees; the reaction from the heated manure, in turn, helps run both the generator and power other parts of the farm. Unneeded power is sold to the broader electric grid.

What's left: Lagoons of wet manure, minus the toxins - and suspended solids, an odorless remnant of cow dung that is used for cow bedding.

And lest we forget that farm animals do more than poop, the Brits are experimenting with converting sheep urine into fuel:

An unusual source of fuel is being trialled as a way of cutting down on emissions and saving energy: a bus in Winchester is to be fitted with a tank of sheep's urine.

The "fuel" is being used by bus company Stagecoach in a bid to reduce emissions of harmful nitrous oxide, with the urine sprayed into exhaust fumes to achieve this effect.

Andrew Dyer, managing director of Stagecoach South, told the Guardian: "It is a novel way of reducing pollution but we believe it will work."

The Hampshire county council-backed scheme sees urine collected from farmyard waste and refined into pure urea, which contains ammonia that reacts with nitrous oxides in exhaust fumes and neutralises them.

Mr Dyer added that while the source of fuel might seem unusual, it could provide a realistic alternative in the fight to cut down on emissions.

"I got some laughs when I told a transport conference in Birmingham that sheep urine could be the key to cleaner vehicles but it is becoming a reality," he explained.

"This is the latest in green technology and we believe it will help make our cities better places to be for the public."