This is a cool article from a farm near my father-in-law's farm in Colombia. This farm, called Tosoly, has a closed-cycle system wherein it feeds hogs with cane juice and malanga leaves, the hogs produce poop that turns into biogas for the household and fertilizer for the fields, and the sugar cane bagasse (the woody leftover stem after you take out the sweet juice) is gasified to produce electricity for car and household. There's also a bunch of forage trees to feed goats on the farm.
Anyway, the article calculates how much electricity can be produced from the 2.5 ha used for hog and goat forage, as well as the carbon-storing valued of the biochar left over after gasification. All pretty cool stuff.