BoingBoing recently linked to an article from The New Atlantis about why using hydrogen as a fuel source is not feasible. The main argument against hydrogen is that it requires more energy to produce than that hydrogen will release upon oxidation (burning). Their secondary argument against hydrogen fuel is that in order for hydrogen to power a car for the same length trip as the average gasoline powered car now-a-days would require a much larger and more dangerous fuel tank. Both the arguments are true but they are definitely not good arguments as to why we should not focus scientific and economic efforts into producing hydrogen as a fuel source. The rest of this post will be a rebuttal to those two arguments from The New Atlantis.
1. Hydrogen requires more energy to produce than it can release. True. However, this is not really a problem. In China a new type of high temperature nuclear reactor, called a pebble-bed reactor, has been developed that uses uranium embedded in graphite balls to heat helium gas. The gas can heat up to about 1600 degrees Celsius without causing a meltdown. In fact due to the physics of expanding gas the nuclear reactor is meltdown safe. This alone is great from an environmentalist perspective: it will generate a huge amount of electrical energy without producing any carbon dioxide. The uranium fuel, once used up, is then embedded in a form of silicon and is safe for at least one million years, virtually 100% safe from leaking into any lakes or rivers as is the worry with previous nuclear power plants that use water vapor to drive the turbines instead of helium. The high temperature that the reactor reaches, along with the massive amount of electrical energy produced, can be used to produce hydrogen gas from water. The energy gained from these nuclear reactors would be more than enough to create a sustainable supply of hydrogen as well as producing electricity for cities and cars.
2. The tanks required to store hydrogen will be too massive and dangerous for conventional cars. This statement is true if the car is being powered solely with pure hydrogen. However, rechargeable battery power is getting better all the time and the amount of fuel necessary to power an electric/gas hybrid car is dropping. Organic polymer technology is also getting to the point that organo-synthetic casings will be light enough and cheap enough to hold pressurized hydrogen. Finally, the promise of solid hydrogen fuel is lessening the worry of the ultra-cold, high pressure, hydrogen fuel tanks altogether. In Seoul, South Korea, a physics group has found that they can get hydrogen to bind to titanium with no energy input and extract it back out with very little energy. This solid titanium-hydrogen combination does not need to be ultra-cold or under high pressure either, which will hopefully lead to safe compact solid-fuel hydrogen tanks.
Toyota last year put some hydrogen fuel-cell cars on the streets and because of a partnership between GM and Shell even more hydrogen fuel-cell cars will put on the roads in the next couple years along with new fueling stations. Hydrogen and nuclear power derived electricity is the future for cars and all energy in general, it's time the public and government took this more seriously in order to prevent global warming and also to prevent wars over resources as is the case with Iraq.
Some of my sources and further reading:
Platinum Today - Hydrogen binding to platinum for solid fuel.
Wired Magazine - Pebble-bed nuclear reactors.
BBC - General Motors and Shell partnership.