Fort Collins, Colorado.

   Coming soon: a manufacturing system and a new technology which will make possible the mass production and marketing of photovoltaic (PV) products, especially PV or solar cells.  Using the sun's energy, these cells create electricity renewably that can be used to produce hydrogen from water. 

   Advocates of a hydrogen economy are eagerly awaiting the completion of a ten-year undertaking by AVA Technologies, Inc. of Fort Collins, Colorado.  Walajabad Sampath, Ph.D., project leader, and research associates Al Enzenroth and Kurt Barth, members of the Mechanical Engineering Department at Colorado State University, are coming close to the end of a long journey. 

   With assistance from graduate students, the three-man team is working to perfect an efficient, low-cost manufacturing system capable of converting ordinary glass into solar cells. "We have overcome all the technical hurdles.  It will take us another year or two to address some engineering issues, but they are solvable," Barth said.

   Their goal is to create an economically feasible manufacturing process capable of supplying the demand for photovoltaic products that is growing at a rate of 25 percent each year.   With the current energy crisis in California, demand for PV products has far exceeded supply. 

   Although PV cells have been around for a half-century, until now they have been too costly for widespread use.  According to Sampath, the raw material for a PV cell represents only a tenth of the total cost.  Expensive manufacturing processes are responsible for the rest. 

   Currently 85 to 90 percent of the world's PV products are made from crystalline silicon, available in limited quantities and therefore becoming more expensive.  AVA has discovered a way to coat ordinary window glass with a thin film of cadmium telluride (CdTe), a waste product from the processing of copper, to create the cells.  The thin film process uses up to 100 times less semiconductor material than the crystalline silicon process requires. 

   An equally important advantage of the new system is the air-to-vacuum-to-air (AVA) high-throughput vacuum process the team has developed for depositing the thin coat of film on the glass.  Because substances in the air such as nitrogen and oxygen bombard and disrupt the surface of the precise layers, the film must be applied in a total vacuum to achieve acceptable results.  Current techniques are time consuming and labor 
intensive. 

   In the AVA system, a continuous-belt conveyor transports the glass from the air to the vacuum chamber and to the air again.  All phases of the process occur in a single vacuum chamber resulting in efficiency, high quality and uniformity. "Our goal is to produce a 12" by 12" PV cell every two minutes," Sampath says. 

   The research team is currently operating under a grant from the Inventions and Innovation Program of the U.S. Department of Energy.  The program offers financial assistance for the development of ideas that have significant energy savings impact and market potential.