My end of the year project for my Environmental Science class this year was to teach a segment on fuel cells in general, hydrogen in particular, so I'm going to do a quick infodump to clear up any misconceptions.
First thing to realize:
hydrogen cells do not create electricity. They can create a current using a reactant and oxidizer, but the energy input to form the reactant is always higher than the energy output. Any such claims about a hydrogen fuel cell car running forever are undiluted bull****, and I encourage you to send me links to any articles that claim to have invented one so that I may laugh at them.
Second thing:
fuel cells do not work at 100% efficiency. It should be obvious that there will be some energy loss, but in operation the efficiency can be anywhere from 45-17%. For comparison, internal combustion engines run around 22%, depending again on specifics. As an added penalty, that 45-17% efficiency is from the fuel to the wheel, and completely discounts any loss in the generation of electricity needed to form the fuel.
Third thing:
fuel cells are expensive. A working fuel cells needs a platinum catalyst to speed the reaction. Platinum is rather obviously expensive. Another fancy doohickey in a fuel cell is the Polymer Electrolyte Membrane (PEM), which is needed to turn an uncontrolled oxidation reaction into electricity. The PEM is made out of nafion, which is a complex artificial hydrocarbon. Complex = expensive. The platinum is absolutely vital, but early experiments using graphite instead of nafion for the PEM have shown a cost decrease from 400 euros/m^2 to 4 euros/m^2, albeit at a drop in efficiency. More research is needed, and could prove fruitful.
Fourth thing:
fuel cells are reliable. Oh sure, screw up the fuel regulation an the cell explodes, but get past that (and operator error. If you build it, they will be dumb.), and you have an efficiency rating of 99.9999%. I did not make that number up, this really does only need
15 minutes of maintenance per century.
(roughly)
Fifth thing: no emissions. That's ignoring the liquid water, mind you. I personally don't find water to be that big a problem, though.
As for the whole fuel cell v. gas issue, I'm holding out for maglevs with on-board annie plants. For those trapped in the 3rd millennium, however, my money's on hydrogen. The infrastructure still needs to be developed, and the comparison right now is pretty even, but hydrogen's a new field while gas has been invented and reinvented for the last hundred years. I think it's time for a paradigm shift.
As for ethanol: no. I only have three reasons, but they're pretty good ones:
- Farmers that are growing fuel corn are not growing food. I like food, how about you?
- Pursual of ethanol technology will need to be backed by government funding to make it economical, and will draw away from other fields of progress.
- FOR CTHULHU'S SAKE, IT'S NOT EVEN WORTH IT! Modern industrial agricultural practices use gas and nitrogen fertilizer, so every calorie of ethanol produced uses ten calories worth of crude oil! The point here is to save oil, not burn it! (pun not intended)
), the thread was closed and then deleted... I miss it so much so I made a decision. Re-institute the Enlightenment Thread! 
