Pennsylvania dairy farmer Shawn Saylor's anaerobic digester produced an amazing 1.2 million kilowatt hours of electricity last year, according to an article in Popular Mechanics.. The cow power digester saved Saylor's farm $60,000.

The coolest thing about the digester is the 40-foot-diameter rubber bubble that holds extra bio-gas that's used to run a generator. The bubble buffers the gas flow from fluctuations. The device cost $800,000 to construct, most of that covered by a grant.

I've blogged about cow-lowatts -- in part, because I love the idea of turning one of the worst byproducts of farming into heat and light. As a (big) bonus, making electricity out of cow pies puts a heifer-size dent in the stink factor of your average dairy.