Photosynthesis is one of the coolest techniques in nature, but also something of a mystery; something we've had a hard time reproduce. Efforts to understand the efficiency of the process has been underway for a long time, and I recall seeing claims about quantum coherency in the antennae proteins picking up the photons (though that was some time ago, and things might have changed). Anyway, a recent post in MIT Technology Review has some information about research at Caltech that supposedly creates an 'artificial leaf':
The technology harnesses the sun's energy to split water into hydrogen and oxygen; the hydrogen could be used as fuel for vehicles or be stored for use in generating electricity. A photovoltaic material captures photons and generates electrons, which are passed on to chemical catalysts to do the water splitting.
This is awesome news if it can be scaled up. Given that we have enough water… Excited to see how it progresses.