Answers (1)
Never heard of it. Got a link?
Biogas generators in general are widely used:
www.google.com/search?newwindow=1&site=&tbm=isch&source=hp&biw=819&bih=938&q=liberty+bio+gas+generator
Of course you have to get practical: it's not hard to generate enough gas to run a stove, but any more than that requires a small ranch to feed the system.