Engineer-poet had an interesting analysis of a comprehensive program of biofuels.
He suggests this program for the nation:
* Finance the fastest practical development and pilot test programs for solid-oxide fuel cells, molten-carbonate fuel cells and especially direct-carbon fuel cells. Processing systems for biomass carbonizer off-gas to feed SOFC's should be a priority.
* Block the issuance of permits for any coal-burning powerplants without plans for full carbon sequestration.
* Require most new vehicles to be PHEV's.
* Promote or require plug-in facilities for new or renovated construction.
* Some sort of net metering or other feed-in law is required for the grid.
* Get rid of all preferences and mandates for alternative fuels; incentives should be created by taxes on oil, coal and natural gas.
I would note that my previous article shows that even an highly optimistic view of PHEV would take until about 2040 to replace current cars. As I have noted, coal kills one million people per year, so it is still necessary to get more nuclear power, solar and wind as well so that coal and oil can be replaced sooner. Also, since it is unlikely that the above recommendations will be fully implemented and we cannot depend on any single technology or solution panning out, we should try to move forward with all of the alternative energy options that have a chance for significant impact.
Gains in efficiency need to take into account the growth in demand. Almost everyone in the USA has a car now. In 30 years, most people in China, India and other countries will also have cars (even if there is a lot of highly successful mass transit systems and policies). 600 million cars now will be about 2 billion or more in 30 years.
Engineer Poet has a blog ergosphere