'Major discovery' from MIT primed to unleash solar revolution

July 31, 2008

http://web.mit.edu/newsoffice/2008/oxygen-0731.html

Anne Trafton, News Office
In a revolutionary leap that could transform solar power from a marginal, boutique alternative into a mainstream energy source, MIT researchers have overcome a major barrier to large-scale solar power: storing energy for use when the sun doesn't shine.

Daniel Nocera describes new process for storing solar energy
View video post on MIT TechTV
Until now, solar power has been a daytime-only energy source, because storing extra solar energy for later use is prohibitively expensive and grossly inefficient. With today's announcement, MIT researchers have hit upon a simple, inexpensive, highly efficient process for storing solar energy.
Requiring nothing but abundant, non-toxic natural materials, this discovery could unlock the most potent, carbon-free energy source of all: the sun. "This is the nirvana of what we've been talking about for years," said MIT's Daniel Nocera, the Henry Dreyfus Professor of Energy at MIT and senior author of a paper describing the work in the July 31 issue of Science. "Solar power has always been a limited, far-off solution. Now we can seriously think about solar power as unlimited and soon."
Inspired by the photosynthesis performed by plants, Nocera and Matthew Kanan, a postdoctoral fellow in Nocera's lab, have developed an unprecedented process that will allow the sun's energy to be used to split water into hydrogen and oxygen gases. Later, the oxygen and hydrogen may be recombined inside a fuel cell, creating carbon-free electricity to power your house or your electric car, day or night.
The key component in Nocera and Kanan's new process is a new catalyst that produces oxygen gas from water; another catalyst produces valuable hydrogen gas. The new catalyst consists of cobalt metal, phosphate and an electrode, placed in water. When electricity -- whether from a photovoltaic cell, a wind turbine or any other source -- runs through the electrode, the cobalt and phosphate form a thin film on the electrode, and oxygen gas is produced.

http://blog.wired.com/wiredscience/2008/07/reverse-fuel-ce.html

A new catalyst makes it feasible to split water with solar power.
MIT chemists say the catalyst, used in conjunction with cheap photovoltaic solar panels, could lead to inexpensive, simple systems that use water to store the energy from sunlight.
In the process, the scientists may have cleared the major roadblock on the long road to fossil fuel independence: Reducing the on-again, off-again nature of many renewable power sources.
The catalyst enables the electrolysis system to function efficiently at room temperature and at ordinary pressure. Like a reverse fuel cell, it splits water into oxygen and hydrogen. By recombining the molecules with a standard fuel cell, the O2 and H2 could then be used to generate energy on demand.
"You've made your house into a fuel station," Daniel Nocera, a chemistry professor at MIT said. "I've gotten rid of all the goddamn grids."

http://blog.wired.com/wiredscience/2009/01/top-10-scientif.html
Companies like Nanosolar and Solyndra slashed the cost of solar energy, but scientists are still looking for a clean way to store all that juice. Daniel Nocera of MIT has an elegant solution: Use electricity to break water into hydrogen and oxygen, store it in separate tanks, then recombine the gases in a fuel cell when you need power.
Anyone can do this. Just hook a 9-volt battery to electrodes and dunk them into a jar of water. The problem is that it takes a lot of energy to do this. If you want to fill tanks with those gases, and use them to run a fuel cell, you'll need to do it very efficiently. Nocera, and his team at MIT, found a catalyst that makes the task of splitting H2O remarkably easy. It could store the energy harvested by solar cells and wind farms.