Les Jones

Environment > Hydrogen Car Challenges

Technology Review piece on the hydrogen-powered BMW:

Still, the company has gone further than any other in regulating the combustion of hydrogen. Just three years ago, the engine would run for several minutes and then break down with a big bang, says Melcher. "Boom. We love explosions!" he laughs. It turned out that a little bit of hydrogen was leaking past the pistons, mixing with oil, and exploding. That problem was solved by modifying the piston rings to prevent leakage. Engine control systems also had to be modified to deal with the far faster combustion of hydrogen--it burns 100 times faster than gasoline--and to regulate it in such a way as to keep emissions of combustion byproducts like nitrogen oxides to trace levels.

Via FuturePundit, who writes:

Hydrogen has 3 big problems as an automotive power source, the first two of which are illustrated in this car:

• Hydrogen fuel cells are not ready yet. Hydrogen internal combustion engines have downsides as substitutes.
• Liquid hydrogen storage does not make the grade due to losses from evaporation while sitting and the need to use energy while operating to cool the remaining hydrogen back down again. Solid room temperature hydrogen storage is needed. But the physicists and materials scientists still haven't solved that problem.
• Hydrogen is currently made using hydrocarbons and the net result is probably less energy efficient than just burning the hydrocarbons directly.