New Artificial Leaf May be Practical For Use In Household Electricity
At the 241st meeting of the American Chemical Society in Anaheim on the 27th of March, 2011, scientists presented what well may turn out to be a breakthrough development: the first practically usable artificial leaf.
While the first artificial leaf was created at the National Renewable Energy Laboratory in Boulder, Colorado, by John Turner, it was not practically usable for a number of reasons: it was unstable, having a life span of one day, and it was made out of rare metals.
This new artificial leaf is made out of inexpensive, readily available substances and has an efficiency of 10 times that of a natural leaf. It looks nothing like a plant leaf - about the size of a playing card but thinner, and made of silicon and other high-tech compounds. It basically does what photosynthesis does, namely splitting water into hydrogen and oxygen. Daniel Nocera, Ph.D. at the Massachusetts Institute for Technology led the research team. He says that the leaf shows promise for wide practical application especially for poor households in developing countries.
The hydrogen and oxygen which are produced could be led to a fuel cell, which could be placed on top of or behind a house. One cell in a gallon of water in bright sunlight would be capable of producing enough fuel to power a small house.
With funding from the National Science Foundation and Chesonis Family Foundation, the research team developed a solar cell-type device which was capable (under laboratory conditions) to continuously produce electricity for 45 hours. Contrary to the earlier artificial leaf, this device seems to be very stable and it is able to function under very simple conditions.
As said before, the ''artificial leaf'' is not new. In 2010 Professor Dr. Orlin Velev of the North Carolina State University presented water-gel based solar devices with light-sensitive molecules that are capable of producing electricity when stimulated by sunlight. A main difference with current solar cell technology is that this works with a gel structure instead of crystals. The problem with these devices was their efficiency. In order to provide a house with electricity one would need to cover the entire roof of the house with them. Electricity would need to be stored in batteries, which requires quite an investment.
The new artificial leaf, however, could maybe turn out to be a low-cost application.