What about BIO GAS ???? from cowdung !!!

Enclose a volume of cow patties and urine add enough water to cover, Stir and stir till you make a creamy mixture. Put on a tight lid with a pipe screwed to the lid some where, attach a hose to the pipe, add a valve, and the other end of the hose going to an inner tube, add warmth and Presto three to fourteen days later the cow pies are magically transformed to BIO GAS. Suitable for cooking, or running a generator (its only half as hot as propane so you need twice as much). Fortunately cows are free with their organic