Researchers at Colorado State University have been using an ink jet printer to deposit materials on a substrate in order to create what has been called a photoelectrolytic solar cell. Rather than generating electricity when sunlight strikes the cell, the photoelectrolytic cell generates hydrogen by splitting water atoms into its constituent elements. The hydrogen released could be collected and stored for use by a fuel cell or hydrogen burning internal combustion engine.
To be practical, a solar-photoelectrolytic material must not only split water efficiently, but should have a bandgap that is not so large that it prevents most of the solar spectrum from being absorbed; the material should also operate stably for many years in harsh sunlight. The CSU group believes that a nanostructured oxide semiconductor will be the ultimate practical material; it will be deposited on the backside of a glass substrate—allowing for back illumination, which reduces scattering of sunlight. The material, they also believe, will contain multiple metals that, when added together, will create stability, high absorption, and efficient catalysis.
Such a system could be a more efficient way to store solar energy than batteries, such as is done now. It might also be able to generate enough hydrogen to fuel the family automobile, something that should appeal to just about everyone that drives.
Let's hope the folks at CSU succeed in their efforts.
Hmm. I wonder how easy it would be to retrofit my boat for hydrogen tanks, a fuel cell, and that big honkin' electric motor I've had my eye on....