As I calculated in a previous blog entry, there is no hope that biodiesel can replace petroleum. Even if we starved and planted all our land with canola, we could only make about 15 percent of the oil we use.

Photosynthesis is not very efficient, 1 percent, maybe 2 percent for amazing plants like sugar cane or corn. Most of that energy goes into the cellulose in the stems and leaves, so any scheme that only uses a tiny portion of the plant — oil seeds or starch from corn kernels — is taking about 1 percent of that 1 percent. That’s a lose.

Some types of algae have high percentage yields of oil, but aquaculture cannot be applied to a significant percentage of our 400 million acres of arable land. Makes for some nice journal papers and research grants, but I don’t think it will be practically useful.

Where biofuel has worked, people have burned the whole plant for fuel. In Brazil, ethanol is made from sugar cane, but more importantly, the husks are burned to fuel the distillation process. In America, propane is burned, which is just crazy. This is one reason why Brazil gets a 900 percent return on energy from ethanol, and America gets about 100 percent return (about the same energy out as put in). Sorry to be political here, but I believe the US corn ethanol program is a boondoggle promoted by the corn lobby. It is putting pressure on food prices and not solving our energy problem.

Another nice example of biofuel from whole plants is the Florida Crystals operation. They run a 75 megawatt power plant fueled by cane husk and yard waste. This is enough electricity to run their factory and sell power to 40,000 nearby homes. This is not a university experiment, it is a real company that makes a product and a profit, and they are using biofuel.

As with a lot of alternative energy, it is easy to run a large stationary power plant. I honestly do not expect the cost of electricty in the USA to increase much. Coal powered plants can also augment their fuel with biomass. I’m more concerned about applications that need portable energy of high density — tractors and airplanes in particular. Commutor cars can probably be electric, but I doubt if farm machinery, working hard all day, can be operated off batteries. As we enter peak oil, whenever that is, the production of food will be the most important operation to come under pressure.