There's an insidious vision, at least here in the US, that if we just all buy electric vehicles, put up enough wind turbines, and brew enough biofuels, that we will be able to just go on living the way we are living while reducing our emissions, and not worry about the climate. The vision's insidious because it is pretty much the unspoken assumption to everything we do, even amongst otherwise aware and conscientious people.

Well, it's not such a good vision. At least not in biofuels. There are some very strange dynamics to the biofuel industry.

Right now, most biofuel in the US comes from corn. We've got a lot of it after all, and it's got a high sugar content, making it perfect for biofuel production. But corn is one of the most energy-intensive crops to grow, especially if you are doing it with chemically-based fertilizers and pesticides. Include the energy for harvesting, transporting, and processing, and you're lucky to break even from an energy perspective. In industry parlance, the Energy Return on Investment (EROI, or the number of units of energy you get for use, divided by the number of units of energy it took to get it) is pretty darn close to 1. Some argue it's actually less.

The EROI is the Key Performance Indicator for energy systems. We used to get oil out of the ground at EROIs of 25 or more (i.e. a single barrel of oil energy extracted 25 barrels of oil from the ground.) Today we're looking at an EROI for oil closer to 14 or 15. So you can see what an EROI of 1 counts for. If it weren't for government mandates, biofuels would likely be abandoned. They don't support the dream.

The double-whammy is that as oil prices rise the times when you really want to rely on your biofuels the cost of growing corn goes up as well because of all the energy it takes to grow, transport, and process. It is no where near a self-perpetuating industry yet, one able to supply its own energy needs. Add to this the devastating impact that using corn for biofuels has on world food prices, and it's no wonder that several environmental organizations have backed away from it.

So the next generation, the next miracle plant that will keep our vision alive, is switchgrass. Really much cheaper to grow and harvest. The energy density per plant is lower, but the energy density per kilogram is workable. And certainly no one is taking switchgrass out of the mouths of the world's hungry.

The catch is that converting switchgrass to biofuel takes more energy than using corn, where the sugars are so much more available. The pre-harvest process takes less energy. But the post-harvest process makes up for it. The upshot is that we shouldn't expect an EROI much greater than unity for switchgrass either.

The proper vision is that biofuels will be a critical part of the post-Peak Oil infrastructure. But they won't be a panacea. Indeed, aircraft and heavy equipment will likely never run on batteries. The energy demand is just too high. There are other energy hungry applications as well. So we need to reset our vision of biofuels, and aim for the proper goal. They'll get a lot less bad press that way too.