No Silicon Solar | Green Energy News

August 4, 2002 – Vol.7 No.19

NO SILICON SOLAR.

Drastic cost reductions of solar power are needed if it is to seriously compete as an energy source in a world flooded with cheap fossil fuels. Various methods are now underway to reduce the cost of silicon photovoltaic solar energy. Improved production techniques (Bakaert ECD Solar Systems) or the replacement of sliced silicon wafers with silicon spheres (Spheral Solar) are examples. But in the end the real breakthrough in solar energy may come with the replacement of silicon altogether in solar cells.

Australian company Sustainable Technologies International claims to be the first in the world to begin manufacturing (on a small scale) Titania Dye Solar cells (DSC). The company describes the technology as a photoelectrochemical cell - more like the leaves of a plant - not a photovoltaic (PV) cell. Each cell is a sandwich of titanium dioxide (TiO2) nanoparticles, dye, electrolyte, catalyst between two layers of conductive glass. Light passes through the glass and the titanium dioxide particles to excite the dye which releases electrons which the TiO2 layer then captures and sends off as flowing electric current.

According to the company the cells can be made in a simple process that can be automated, and the entire, full cycle, manufacturing process - from raw materials to finished product - is not energy intensive. (Most of the energy needed to make the cells is to make the glass layers.)

Sustainable Technologies also says that the cells can also be translucent or transparent and can be built into buildings for daylighting applications. The technology is especially well suited for temperate and moderate climates - places on the planet where sunlight shines down at an angle. DSC also works well in partial light conditions, even indoors.

The company does not mention the efficiency DSC, but for now, since this technology is in the early stage of development, expect efficiency to be low. However, efficiency is not that important if cost is low. The company claims to be manufacturing the cells for sale, as well as the chemicals for others to make them, but apparently needs to be contacted directly (by e-mail) for possible purchase of either - try catalog@sta.com.au . Visit Sustainable at http://www.sta.com.au/ , Bakaert at http://ovonic.com/unisolar, Spheral Solar at http://www.spheralsolar.com/