Mark sent along this story about a biotech startup, gently nudging me to break a long blabsence (I’ve been on the road for two weeks raising my carbon footprint, doing biofuel stuff). They are among a bunch of tech entrepreneurs with promising very early stage technology to leapfrog the millenia-old technology of yeast fermentation (and centuries-old technology of distillation), using genetically designed organisms that can turn biomaterials directly into fuels. LS9 needs a good source of sugar or fatty acids; another hot property is Coskata, with a different approach that will take any cellulosic material whatever. Meanwhile, the algae folks are trying to figure out how to grow algae in tanks in the desert (no food cropland required) that make diesel that floats right to the top of the tank.
I have no idea which of these will get to an economically workable engineering state first, or whether any of them will. (I’m pretty sure we’re not investing enough public money in the whole research enterprise, though.) Back during my first energy crisis, flywheels were on this list, and the materials scientists were just this far from a drop-dead perfect battery that would give us an electric car with a thousand-mile range. Of course, during that one “four hundred years of coal” was reassuring rather than a doomsday curse…
Global warming has put coal under a serious cloud, of course, hence the appeal of biofuels. I say, two cheers for biofuels at best. The reasons for the tepidity of my enthusiasm are two. First, all of these new production technologies are vaporware: good ideas with no fundamental thermodynamic violation (not perpetual motion machines or magic) each of which will probably fail tests of economic viability or practical operability at large scale, though one or more among them may well fly and all are definitely worth pursuing. LS9, for example, awaits a practical way to turn cellulose bound with lignin (plant stalks, stems, leaves, and branches as opposed to seeds with starch) into sugars, and that’s another technology that may spend a while on the brink of practical application, for example here and here. Second, and more important, biofuels require biofeedstocks, and the largest category of these, purpose-grown crops grown on farmland, now appear to be non-starters if global warming is what we’re trying to stop. It appears increasingly likely that any biofuel that uses arable land is worse, probably much worse, than fossil fuel because through its competition for food-growing land, it induces conversion of forests and grassland around the world to farming. This conversion, through the burning or decay of the plants already on the land, releases such an enormous puff of carbon right at the start that the biofuel takes as long as a century to make up for it. (Sugar cane, grown in the right places, may be an exception; more on this when I get back from Brazil in July. Also, abandoned and degraded land in places where there’s enough water to get started may be a good place to grow some biofuel crops.)
There remain biofuel feedstocks that don’t have this liability (so-called iLUC for indirect land use change), like plain old trash and the slash and bark from timber harvesting. But quantities of these are limited and they cost a lot (and a lot of diesel fuel) to gather up and bring to a refinery.
The bottom line here: one more time, there’s no single solution to global warming or energy security. Pacala and Socolow identified fifteen so-called “wedges” of which any seven would stabilize carbon. These wedges are big: one is to double world nuclear power capacity, another is to halve carbon emissions from surface transportation, and so on. Replacing a third of auto gasoline with very good biofuel is about a quarter of a wedge. So by all means, lets keep pushing the technological envelope on biofuels, plug-in hybrid cars, reducing vehicle miles traveled (and conservation of all types), solar electric power, and all the rest, partly because they’re all risky and partly because we need all of them, not one big technotrick. What’s wanted is not a silver bullet, but a shotgun cartridge with a lot of silver birdshot.