MIT Professor Develops Solar Leaf, Could Lead to Cheaper, Cleaner Energy
Tuesday, March 29th 2011 3:57 PM
By GetSolar Staff.
Often, when scientists are pressed to come up with new ideas and innovate in a given field, they look toward nature to see how organisms naturally deal with obstacles. A professor at the Massachusetts Institute of Technology did just that when he was ascertaining the best way to develop clean energy.
Daniel Nocera, a chemist at the world-renowned school, has been studying renewable energy sources for some time. Instead of using nuclear, wind or fossil fuel to power homes in the future, Nocera is a firm believer that solar technologies are capable of generating electricity more cheaply - and more efficiently - than other technologies.
The first problem engineers face when designing clean technology products is how to make them function at a level that ensures the highest level of efficiency. Nocera turned toward nature and designed a solar powered device roughly the size of a pack of playing cards that can break water down into hydrogen and oxygen, which are both inherently valuable in the generation of electricity.
The science the solar technology is based upon is familiar to anyone who has taken a science class in his or her life. During photosynthesis, plants turn light energy into chemical energy and store it for later use. Plants take in carbon dioxide from the air and use the energy from sunlight to convert it into organic compounds like sugar that help fuel its cellular operations.
Taking a cue from the green plants that people are in contact with every day, Nocera developed his "artificial leaf." Using a catalyst he had also developed that breaks down water molecules using low-voltage output from a solar cell, Nocera chemically painted the catalyst onto a solar cell and immersed it in water.
At a meeting of the American Chemical Society in Anaheim, California, on Monday, Nocera answered questions about the solar technology, affirming it is capable of creating energy from water using sunlight. "We could put it in a bottle of water, hold it up to the sun, and you would start seeing hydrogen and oxygen bubbles coming off," Nocera said.
While the technology is complex, Nocera told attendees at the conference that the leaf works like one in nature would, using sunlight to produce electrons and positive charges that then split water into its original molecular composition of two hydrogen and one oxygen molecules. "Whether you realize it or not," Nocera asserted "leaves are buzzing with electricity."
In Nocera's artificial leaf, a silicon chip produces electrons and positively charged holes; afterwards, catalysts on the chip use that low-voltage current to generate oxygen and hydrogen, with each gas occupying a different side of the chip. While the technology has been created before at Colorado's U.S. National Renewable Energy Laboratory, Nocera's leaf is made entirely from cheap materials, which could fuel its use.
Nocera's technology is far from hitting the market commercially, though. He affirms that he is still developing more innovative ways to capture the gases created in the solar leaf. "There's got to be some tricky engineering to collect the gases as they're coming off the silicon," Nocera said. "We don't know how to do that yet."
Ultimately, Nocera's solar leaf technology is so promising because it could potentially cut the need for traditional solar panels. While solar module costs have fallen over the past decade, they are still a considerable investment because of the complex wiring systems needed to connect them to the electrical grid. "The price of the silicon of a solar panel isn't much," Nocera said. "A lot of the cost is the wiring. What this does is get rid of that."
The "real goal here," Nocera affirmed, "is giving energy to the poor." Nocera's catalyst has caught the attention of Indian company Tata, which analysts aver is interested in deploying the technology throughout the nation. The promise of creating energy with little or no wiring necessary is something that has attracted lots of attention from around the globe - including right here in the U.S.