Energy storage by mimicking photosynthesis

By Daniel Collins 19/03/2010 2

From my old alma mater, MIT chemist Dan Nocera has developed a method to store energy that mimics photosynthesis – by splitting water.

The key is having the right catalyst, and one that is cheap to make and maintain. In this case, a film of cobalt and phosphate coating an electrode. When fed a modest electric current, say from a solar panel, water is split into oxygen and hydrogen gas. This doesn’t produce energy, it just stores it in the form of two gases. When the sun goes down, the H2 can be oxidised with a fuel cell, producing electricity and water again, and the cycle can be repeated the next day.

Visit Science to see footage of the process, listen to a podcast or read the abstract (published in 2008 – okay, I’m a little slow, but it’s all Scientific American’s fault).

Nocera is very gung ho about improving the human condition and educating young minds:

“In the energy game, young people can choose lots of different paths. I’m just asking them to save the world.”

2 Responses to “Energy storage by mimicking photosynthesis”

  • But this is not new… it’s just another energy storage technique. The breakdown of water is presumably pretty efficient (I didn’t think that the catalyst would be terribly important, but apparently I was wrong about that, at least), but what about the other conversions? How does this compare to storing energy in the battery of your electric car? Or “storing” it in a nationwide or continentwide grid, or using any of the other load-balancing techniques we’ve had for years? What does this energy-storage technique let us do better?

  • Well, the tech is still young, so we don’t know how its efficiency and scalability compares with other techs. The app that Nocera seemed to be eying was in the developing world, where dirty water can be found but many other techs cannot. That is, of course, provided that this tech is cheap and robust enough.