Get Your Learn On, Part Deux:

One persistent myth about biomass is that it takes more energy to produce fuels from biomass than the fuels themselves contain. In other words, that it is a net energy loser. In fact, current ethanol production uses corn, one of the most energy-intensive crops, and then uses just the kernels from the corn plant, and not even the entire kernel. Even so, this process yields 50 percent more energy than it takes to make the ethanol, so it is a net gainer.

Nonetheless, we could do much better. By making ethanol from energy crops, we could obtain between four and five times the energy that we put in, and by making electricity we could get perhaps 10 times or more. In the future, to make a truly sustainable biomass energy system, we would have to replace fossil fuels with biomass or other renewable fuels to plant and harvest the crops.

Another important consideration with biomass energy systems is that biomass contains less energy per pound than fossil fuels. This means that raw biomass typically can't be cost-effectively shipped more than about 50 miles before it is converted into fuel or energy. It also means that biomass energy systems are likely to be smaller than their fossil fuel counterparts, because it is hard to gather and process more than this quantity of fuel in one place. This has the advantage that local, rural communities -- and perhaps even individual farms -- will be able to design energy systems that are self-sufficient, sustainable, and perfectly adapted to their own needs.

I dunno about those ethanol numbers. One thing a lot of people forget to calculate is that we use petroleum products when making fertilizers. That's right: we treat our sewage and cesspool our animal waste so that it can re-enter the water supply, and we pump dead organic matter out of the ground in the middle east to make stuff to spread on our crops so they'll grow better.

Yeah, that's fucking market efficiency for ya.