Porsche. Oil. There is no [easy] substitute.

This is a very interesting article and research paper on energy alternatives. The stock market clearly supports solar and doubts ethanol, and the data in these support those views. We're a long way off from the vision of solar charged vehicles on a mass scale though.

MSN Money: Shuck the ethanol and let solar shine.

Quotes:

New research by a University of California petroleum engineering professor suggests that worldwide crude oil supplies will start to run so low over the next nine years that resource-blessed countries like Saudi Arabia will begin to hoard them for domestic use instead of exporting -- and states with large reservoirs of natural gas, like Montana, will seek ways to avoid sharing with less-advantaged neighbors like Oregon.

Attempts to forestall the political and economic damage by turning aggressively to agriculture for "renewable" transportation fuel in the form of ethanol will prove futile, according to professor Tad W. Patzek, as new calculations show that the entire surface of the Earth cannot create enough additional biomass to replace more than 10% of current fossil fuel use.

....

One better solution is solar energy created at the municipal level by massive photovoltaic cell facilities, at the street level by home-based grids and at the transportation level at lots where electric vehicles' batteries can be charged. Photovoltaic cells lose only about 80% of the sun's energy to dissipation, making them at least 100 times more efficient than ethanol after the fuel cost of growing and refining the biomass feedstack is accounted for.