Those seeking alternatives are looking to algae and cellulose-based plants, like switchgrass. These plants don't cut into with food production because they are not based on grains. In addition, they can be grown in conditions unsuitable for most crops, so they don't use needed agricultural land.
Algae and switchgrass might do what corn-based ethanol was supposed to: reduce U.S. dependence on foreign oil and cut CO2 emissions that could cause climate change. Some scientists in the biofuels industry promote algae as a viable alternative to gasoline because it can help curb global warming. Algae require CO2 and sunlight for photosynthesis. Since algae feed on CO2, growing algae goes hand-in-hand with reducing CO2 emissions.
Ted Aulich, a process chemist at the Energy and Environmental Research Center at the Univ. of North Dakota gives algae a glowing recommendation. "Algae represent a better feedstock than just about anything else out there in terms of its CO2 balance," he said, "and also I guess the potential for developing much more economical fuel pathways."
One reason is algae's ability to grow under conditions unsuitable for most crops, Aulich said. Algae can grow in the desert, for example. It can also grow in saline or polluted water that's unusable for anything else.
Besides algae, there's our old friend switchgrass:
Another biofuel considered to have great potential is cellulosic ethanol, made from plants with high cellulose contents -- notably switchgrass. Like algae, switchgrass isn't a food-based crop. It can also grow on marginal land.
Joachim von Braun, director general of the International Food Policy Research Institute, called for an end to food-based biofuel production last week. His institute supports a move toward non-grain crops.
But questions still remain. "We have been saying that there should be a switch to using plant residues or switchgrass or whatever," said the IFPRI spokesman Michael Rubinstein, "but we can't say yet what the impact would -- be because the technology isn't there. Nobody's proven yet that these technologies work."
Yet, some firms have developed working technology to convert algae and switchgrass into fuels. As with many other green energy solutions, the major obstacle for both algae and switchgrass biofuels is not technology but cost.
"We have to figure out a better way to get high yields of algae more economically," Aulich said. He says this means developing technology that will allow more algae to be exposed to as much sunlight as possible.
As for switchgrass, Aulich says the costs of production and transportation are still too high. "It's fairly expensive to harvest and transport switchgrass," he said. "It's not a very energy-dense material. … If we're looking at crops like swichgrass and cellulose crops, what we need is a good way to densify those materials -- increase their energy density." The idea is to get more energy out of less switchgrass, increasing efficiency and cutting costs.
I'm sure there are drawbacks, but one of the things we have to change our mindset about is definitely "whether we can do this." We have to do this. We have to look at wind and solar power, and we have to look at algae and switchgrass.