quarta-feira, 16 de dezembro de 2009


Personalized Energy | MIT World

About the Lecture 
Daniel Nocera is swimming very hard against the current of mainstream energy research. While many scientists are figuring out how to scale up wind, geothermal or biomass systems, Nocera is focusing on “personalized” energy units that can be manufactured, distributed and installed on the cheap. His main concern lies with the increasing energy demands of six billion people, primarily from developing nations, who will be marching onto the world stage by 2050 and likely doubling the planet’s energy consumption, from around 13 to 26 terawatts (that’s trillion watts). A “solution to the energy challenge rests in providing the non-legacy (developing) world a carbon-neutral, sustainable energy supply,” says Nocera.

Nocera’s science isn’t about making big or efficient systems. For non-legacy populations, “cost means everything and efficiency is secondary.” Nocera’s metrics look at cost in terms of energy stored per weight of something, and so he plots a Boeing 777 plane, etching tools, and Big Macs on the same cost curve. Priced out this way, cars cost around $1 million. Pursuing this logic, Nocera wants to build large quantities of small energy systems and get them into the developing world before giant infrastructure-based energy takes root.

Nocera’s vision builds on major research breakthroughs: He has figured out how to harness critical biological processes that may bring widespread solar power closer to reality. Nocera’s innovations include replicating in the lab the process of photosynthesis in plants, using sunlight to split water molecules and store energy. “Chemically, I’m not doing anything in a sophisticated way…just taking water, rearranging bonds and making fuel.” A liter of water, energized by sunlight from a photovoltaic cell, can store 13 megajoules. The 3.2 million liters in MIT’s pool could yield 43 terawatts – enough energy “to take care of all of you.” Nocera’s photosynthesis uses a cobalt-phosphate cocktail that mimics the mineral-based catalytic process in a plant, and “keeps fixing itself,” running endlessly on such humble fuels as Charles River water. His process even yields pure drinking water from waste.

Nocera’s goal is to make each home its own power station, with photovoltaic arrays on the roof feeding the catalytic reaction that splits water into hydrogen and oxygen. Some of these elements are still pricey or unreliable -- in particular, fuel cells and photovoltaics are troublesome -- yet he envisions villages in India and Africa not long from now purchasing one of his basic systems for $800. While Nocera acknowledges his critics, he views them as institution-bound naysayers: “I always say when the scientists stop fighting, then you’re screwed.”