technology: windows turn rays of sunshine into power - solar panel traffic lights

Andy Corcoran's building can improve energy efficiency by installing windows with new transparent solar panels instead of glass.
Panels are five to ten times cheaper than silicon today.
Solar cells are also efficient.
Michael Gratzel and colleagues from the Department of Chemistry at the Federal Institute of Technology in Lausanne described their patent panel this week (
Page 737, October 24).
The sandwich arrangement of the panels mimic the way plants collect energy from light through photosynthesis to make food.
The beauty of the panels, Gratzel says, is that, in addition to the professional conductive glass that forms the sandwich "bread", they are made entirely of plain material.
In addition, the panels are easy to assemble.
You can make one in two hours, he said.
Through the iodine-based electrolytic fluid to penetrate the light of the upper glass layer (
The top layer of the third layer of "fill)
Apply a layer of dye.
Like the chlorophyll in a plant, this dye captures the energy contained in the package of light, called photons.
The energy of the photon impacts the electrons in the dye to the deepest layer of the three "filled" layers-the titaniumdioxide semiconductor film.
Titanium dioxide is a rich pigment used in a variety of products from paint to toothpaste.
The movie is too thin (10 micrometres)
It looks transparent.
The titanium dioxide layer captures the charge and transfers the electrons to the "butter" of the sandwich-a tin oxide conductive film covering the inner surface of the glass.
Tin oxide under Titaniumdioxide conducts electrons out to work as current.
The ircuit is completed by the upper "butter" layer of tin oxide, which leads electrons back into the dye through the electrolyte.
This design is conceptually different from silicon-
Based on solar cells, because silicon does everything-it absorbs and conducts electrons.
Gratzel said that the key to the system is the microscopic roughness of the thin layer of titanium white ceramics, which makes the layer have a high surface area.
He explained that when taking into account the microscopic profile and texture in the film, the area is 1000 times the actual geometric surface visible to the eye.
This makes it more effective to collect charge flow from the dye above.
He said the panel was converted around 7. 1 to 7.
150 of the sunlight that fell on them converted into useful electrical energy-roughly the same as the silicon battery-generated about watts per square meter of panel.
The difference is cost.
The price of the silicon panel is around 400, while the price of the Swiss panel is between 40 and 80.