Friday, November 20, 2009

Power brokers, pt. 5: Daniel Nocera, chemist, MIT

Again, from Discover

Nocera's "bright idea": Split water to generate hydrogen energy - but do it in a cheap way.

Since he puts it so well himself, this is verbatim:

"Nature is the best solar fuel enerhy storage machine known, so let;s figure out how it works. Light comes in four photons, and then it hits the leaf, and it splits water into oxygen and hydrogen. A leaf makes twice as much hydrogen as it does oxygen, and then it stores the result as a solid fuel. So you've stored the sunlight in a fuel,and the energy is in the chemical bonds. Then you eat that fuel, and you get all the sunlight back out in a time-released way. So you are literally chewing the sun.

"Our lab at MIT invented a process that splits water and performs photosynthesis cheaply, outside the leaf. Lately we've found out we can use the Charles River as a water source. We can use waste streams as water sources. We can use the ocean as a water source. So you can generate hydrogen through artificial photosynthesis whenever you need it. I'm very interested in the nonlegacy world, especially Africa and India. Giving a little kid in Africa 500 watts of energy will change his life. And that's not much energy.

Al Gore has been walking around saying: "Just use the technologies. They're on the shelf. Take them off." But he's gone a bit over the deep end. Yes, we do have the technologies. I have photovoltaics. I can store hydrogen in a fuel cell and get all the energy out. I can build any number of systems for you right now, but guess what? They're too expensive. The reason you need scientists like me to discover my little cobalt phosphate catalyst - the material that can drive photosynthesis outside the leaf and in the lab - is because I'm going to do it cheaply.

"To take care of the average house in a day, you need 20 kilowatt-hours of electricity, which is equivalent to only 5.5 liters of water. To drive that point home, I'm holding the amount of water in my hands that you need to power a very big house on the California coast. That amount of water takes care of that house as well as powering a fuel cell car around town. So that's the future. There's no way to stop it. Nature already did this 2-billion-year experiment and decided on this process, and it's coming soon."

There ya go!

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