The Great Biofuel Hope

Conservation and energy efficiency, negawatts, if you will, represent our very best source of carbon reduction. It's the lowest hanging fruit of all in the search for a way to maintain a climate that will keep feeding us. When LED lightbulbs come down in price, they'll be a big part of saving the climate.

But for those times when liquid fuels seem more reasonable, and considering that a wide mix of technologies will be needed to replace fossil energy, we return time and again to discussing biofuels.

I think James Lovelock summed it up best in The Revenge of Gaia, when he said (emphasis mine):

Just imagine that we tried to power our present civilization on crops grown specifically for fuel, such as coppice woodland, fields of oilseed rape, and so on. These are the 'bio fuels', the much-applauded renewable energy source.

Even if these natural products were used only for transport, to fuel our cars, trucks, trains, ships and aircraft, it would require us to burn every year about two to three gigatons of carbon as bio fuel (a gigaton is a thousand million tons). Compare this quantity with our yearly food consumption of half a gigaton; to grow this much already uses more of the Earth's land surface than may be safe.

And by "safe", Lovelock means that the Earth requires a certain amount of land area for the regulation of its climate and ecosystem services. Otherwise, it will no longer be able to keep the climate stable, which is a function of communities of living things. Without living communities, the Earth would be a bare, baked mudball.

Biofuels, which can really only give a positive energy balance when directly burned, are not going to be a comprehensive solution if they have to be grown from plants. Though if we turn to plants' distant cousins and fellow photosynthesizers, algae, a different story may emerge. Asinus Asinum Fricat looks at the jobs potential for it, and the Energy Justice Network's biodiesel fact sheet says that:

Algae derived biodiesel can be produced in self-contained ponds using salt water and sunlight as the main ingredients (fresh water works, too, but why waste that?). Other input needed to maximize production include CO2 (DOE talks about using power plant exhaust, which would require relatively expensive filtration) and nutrients (silicon and nitrogen). Production of diesel from algae could be done for far less than the current cost of diesel. Algae can also be used to make other products like methane. All of the U.S. diesel needs can be met using only 1-3 million acres of land (about 2-5% of the currently fallow cropland in the U.S. and less than the size of the state of Connecticut).

With regards to land-use, that seems far more reasonable. The problem right now is cost. Algal biodiesel costs $33 per gallon with current technology and the prospect of it gives politicians cover to keep pouring money down the ratholes of corn and cellulosic ethanol. (Via Jill Richardson.)

Pick jaw up off the floor.

So ... negawatts, anyone?

(Photo credit: tuchodi on Flickr.)