Fuel cells today are like steam engine in the 18th century. IMO in 20 years everybody will drive on hydrogen (unless we find something even better).
Fuel cells cars cost $100,000 to $300,000, the same as a Rolls Royce. Direct combustion hydrogen cars which use a classic explosion engine, are not cheap neither. The BMW Hydrogen 7 is not cheap neither and far from a panacea.
read here and
herecritics are saying:
-The hydrogen tank has to keep liquid hydrogen at -250 C ad therefore is leaking inevitably as it heats up.
==> I think the technology has to improve but that may be the most difficult step to make that technology commercialy viable. Liquid Hyrogen is not easy to contain and carry around.
Current thermo-tanks are already jewels of technology. Hard to do better.
-Performance are lower than fuel cells: A fuel cell produce 3x more energy per kilo of hydrogen.
==> However fuel cells cars can't run on gasoline where there is no hydrogen station. That could be a + for the hydrogen direct combustion at the beginning.
-Hydrogen is 4x more expensive (per mile or km) than gasoline.
==> It's price should fall rapidly as mass production is started, amd storage capacity increased.
-Hydrogen pollutes even more than gasoline and diesel because it's produced from methan or oil.
==> The goal is to produce hydrogen from water using renewable sources of energy. There is no industrial facility of any size that does that. But that will come when the new fuel is adopted.
The hydrogen will be 100% clean.
There are also on-board hydrogen production methods which looks very promising.
The process involves generating hydrogen from water onboard the vehicle, which removes the need to store hydrogen in a tank. Fuel-tank design is one of the main challenges facing hydrogen car designers, and at present involves serious difficulties. The insulated cryogenic tank in BMW's Hydrogen Seven demonstrator car, as an example, will lose its entire contents to boil-off in matter of days. This doesn't just strand the vehicle (or compel its driver to use the backup petrol tank): it also means that a fuelled-up Hydrogen Seven can't be parked in an enclosed space, lest a dangerous buildup of explosive gas develop.
But boffins led by Professor Jerry Woodall of Purdue University reckon they've managed to sidestep this snag. In their process, water is combined with an alloy of aluminium and gallium. The aluminium oxidises, releasing gaseous hydrogen which could then be used to fuel a conventional car engine as in the Hydrogen Seven. The role of the gallium additive is to prevent a skin of oxide forming on the surface of the aluminium and allow all the metal to be used.
Woodall came across the reaction by accident in the course of research into semiconductors.
"I was cleaning a crucible containing liquid alloys of gallium and aluminum," he says. "When I added water to this alloy - talk about a discovery - there was a violent poof."
sourceAlso look here.
The last link is a comercial website selling a online books about this technology, but it's worth reading.
While "driving on water" is not possible per se, we learn that this technology can increase your mileage (with gas or diesel) by 30%, 50% or 100%.
