I think the question is wrong. It assumes that the problem is to find a "replacement" for oil, in other words, that all we need to do is replace the oil and everything else will work "the same."

For whatever reason, Americans are locked in to thinking that cities should be designed for cars and that every errand should involve driving somewhere (with the expectation that your destination should furnish your car with a free place to park).

It doesn't have to be that way, although I can understand why a country that burns up 20% of global output of petroleum commuting to work everyday might feel that we need to "replace" oil and that will "solve" the looming crisis.

There are OTHER ways of thinking about a solution that does not involve simply replacing oil. These would include:

* Go back to human-scale cities by increasing density and diversity of housing, businesses and facilities.

* Invest in public transit infrastructure, alternative transportation modes. Mandate walkable metro-centers.

Of course, people won't change unless there's a reason to do so. What I am saying is that "market forces" will push us towards those kinds of solutions INSTEAD of towards an oil replacement. People will be better off if they can adapt to this reality rather than hang on until the bitter end to the idea that the future will involve "happy motoring" forever.