Grassoline: Can we fuel cars with grass?
"Research into sources for biological fuels -- biofuels -- has included everything from chicken fat to wood chips. But processing most of them yields a low net energy ratio -- the amount of energy each unit puts out isn't much more than the energy put into its production. Cost has also been a problem: Techniques for extracting fuels from plant and animal resources are currently expensive, which would be reflected at the fuel pump. But the more researchers crunch the numbers on switchgrass, the more it looks like a good candidate for an alternative fuel source."