When roaming open pastures, cattle can walk up to eight hours a day while grazing but they can't always get as much exercise when confined to a barnyard. One enterprising farmer, however, has invented an ingenious means of getting his herd travelling without moving—and generate a bit of free electricity on the side.
On his farm in Northern Ireland, William Taylor built the contraption above and dubbed it "the Livestock Power Mill." It's an unpowered treadmill set on a steep enough incline that the cow has to keep walking lest she be dumped out the back end of it. There is also a feed bag mounted to the uphill side for encouragement.
The treadmill's action spins an axle that in turn spins a gearbox to drive a 2 kW generator. The single-cow prototype was reportedly powerful enough to run four milking machines. Were the entire 1.3 billion cattle on Earth to walk on these machines for eight hours a day, Taylor figured, they could produce six per cent of the world's power.
lead image: William Taylor via Popular Science