[Captain Kwok]

Yay! A good old biomass discussion!

Ethanol could work for the US in a limited capacity, such as replacing 15% or so of gasoline if developed well. Which is good! Like Jack Smith said, ethanol does not add any net CO2 emissions - like fossil fuels or even synthetic fossil fuels would. Bio-desiel is also gaining popularity, although it's a mixture of various fatty acids.

Corn is the most commonly used crop for ethanol in the US, but there are other alternatives (like Will mentioned, switchgrass etc) that have less environment impact.

Brazil's fuel industry was almost entirely ethanol-based from the mid-70s to the early 90s - until they had too many cars - so they've now got to import some gasoline. The main reason why Brazil was able to do this was sugarcane, which is one of the most efficient plants for making ethanol.

The holy grail of biomass is the ability to degrade cellulose effectively. A number of cellulose-degrading enzymes have been isolated from fungi and have been cloned into E. coli etc. for fermentation of organic materials.

Ethanol is probably best suited to displacing gasoline use, rather than as a power source. It'd be better to develop the other greener alternatives (hydro, wind, etc) for now.

Bio-plastics tend to be made out of cellulose or starch-based polymers and are really just starting to gain popularity. Right now a significant percentage of landfill is petro-plastics that will take forever to degrade, so they'll keep making up a higher and higher percentage of our refuse. You'll probably notice a few of the more green stores using starch-based bags.

Lastly, the hydrogen dream is nice but it's a little ways off. I think it will take the invention of something like fusion power to provide the amounts of extra electricity we'd need to split water into hydrogen. If that happens, then we might get lucky and see a new H2 economy.