If hydrogen is the fuel of the future, the future may be a long time coming. An American Physical Society panel reports that vast improvements in hydrogen production, storage, and use are needed to meet President Bush’s goal of having commercially viable hydrogen cars on the road by 2020. The key challenges:
Production. Hydrogen produced by converting coal or by splitting water with electricity costs four times as much as gasoline. The coal process will require better catalysts to purify the hydrogen and technologies to capture the carbon dioxide released during processing. Electrolysis will require cheaper electricity and a more efficient way to separate hydrogen from water.
Storage. A practical hydrogen tank should power a vehicle for 300 miles and take less than 5 minutes to fill; current technology does not come close. Pressurized gas tanks do not hold enough fuel. Liquid tanks must be cooled to –450 degrees Fahrenheit, which eats up energy; after a few days the hydrogen begins to evaporate. Solid tanks are still in the early stages of development.
Use. The cost of fuel cells must drop to at least one-fourth of their current price ($3,000 per kilowatt generated) to compete with gasoline internal-combustion engines. Cost reductions depend on finding an improved electricity-generating membrane, one that runs efficiently and reliably and does not need the expensive platinum now used.