Solar Power Cells May Cut Bills by One-Third : Electricity: Edison hopes to use the new technology to market a system of low-cost panels for home roofs.
Southern California Edison and Texas Instruments Inc. will announce today development of a new material for generating solar power that eventually could cut electric bills by up to one-third for many Southern Californians.
The new photovoltaic technology, developed in six years of secretive research, is aimed at producing low-cost solar roof panels for residential use. The material looks more like flexible metallic sandpaper than the rigid blue solar cells that have become a familiar part of calculators, highway call boxes and remote communications towers.
By the mid-1990s, Edison hopes to begin marketing a solar cell system that costs between $1.50 and $2 a watt to produce electricity, contrasted with current systems costing $8 to $15 a watt. At such a price, photovoltaic panels would become accessible to most consumers.
“This is a route that no one else has taken,” said Gary J. Jones, manager for photovoltaic projects at Sandia National Laboratories in Albuquerque, a research arm of the U.S. Department of Energy. “This is potentially a neat way to make photovoltaics . . . . It certainly has great potential.”
Edison Chairman John E. Bryson said: “It’s a breakthrough, we believe, at the laboratory level in turning sunlight into electricity . . . in a low-cost manufacturing process.”
The most common solar panels use energy from the sun to heat water, which then is used for showers, space heaters and swimming pools. More expensive photovoltaic cells use silicon materials to turn sunlight directly into electricity.
Although conventional photovoltaic cells are in wide use, demand has been greatest for specialized applications in remote locales. There, the higher initial cost of the solar cells is still more economical than installing electrical power lines.
But Edison will be testing whether the new material could see mass application on the rooftops of Southern California to produce low-cost electricity, particularly during the summer.
For example, the utility estimates that a 10-foot-by-10-foot square of photovoltaic solar panel on the south-facing roof of a home could produce 2,000 kilowatt-hours of electricity annually. The average Southern California home uses 6,000 kilowatt-hours per year. Texas Instruments is already building a plant in Dallas to develop manufacturing techniques to produce the new material in quantity. The two companies will continue development through 1992, when they will decide whether the new cells meet commercial expectations.
Unlike most current solar cell technologies, the new technique uses low-cost, so-called metallurgical grade silicon. Metallurgical silicon costs $1 a pound, contrasted with as much as $75 for the higher grade, said Ted Jernigan, a spokesman for Texas Instruments.
But savings are also expected in production, which Jernigan described as “fairly simple and not at all exotic.”
For instance, whereas most conventional solar cells are sliced from ingots of processed silicon, the new technique forms the silicon into tiny spheres, which are embedded in a mesh formed from heavy aluminum foil.
“Most of the products now must be sliced,” Jones said. “You lose the material between the slices. You can end up losing 30% to 50% of it.”
Edison and Texas Instruments predict that the new technique will lead to substantial cost savings.
“This is a price drop that’s really quite exciting,” said Warren Liebold, an energy expert with the Sierra Club who has followed efforts by several U.S. companies over the past decade to bring down the price of photovoltaics.
“Photovoltaics at that price are going to be much cheaper than nuclear and in the same ballpark as a coal plant for the equipment costs--and then there is no fuel cost,” Liebold said.
Other U.S. solar cell companies have followed different research paths, notably Siemens Solar Industries of Camarillo and Solarex Corp. of Rockville, Md., a wholly owned subsidiary of Chicago-based Amoco Corp.
“Everyone who intends to be a major player in this technology is working on one or more major research avenues,” said Chris Eberspacher, senior director of research and development at Siemens Solar. Siemens bought the former Arco Solar facility in February of last year.
“What we feel is the best opportunity for the future,” Eberspacher said, “are various thin-film photovoltaic materials.”
Thin-film materials are formed, in one technique, by vaporizing the silicon, then spreading it on a surface such as glass, in thin sheets. Solarex is also experimenting with this method. But neither company is yet prepared to test its process on so wide a commercial scale.
“There are no real loser technologies at the present time,” Jones of the Sandia lab said. “But there are technologies that are somewhat more limited than others . . . . I think this falls in with the potential for broad application.”
Edison sees the new material’s best use in meeting electricity needs in Southern California and the Southwest during the peak load period of roughly 2 p.m. to 7 p.m. on summer days, when air conditioners draw heavily on the system. Particularly on sunny summer days, the power produced in this way could be substantial, as was learned at the Arco solar generating plant in the Mojave Desert.
“The reality is that it can generate tremendous amounts of electricity,” said Nick Patapoff, a senior research engineer at Edison.
Texas Instruments hopes to complete its pilot production plant in the next two months.
“We have been involved in research on solar energy for about 40 years,” Jernigan of Texas Instruments said. “This is probably the most exciting development in this area thus far. But, obviously, there is a lot of development work that needs to be done.”
THE NEW CELL
Most solar cells are flat, rigid circles of silicon, generally 4 inches in diameter, which are sliced from larger ingots. Some companies are experimenting with various forms of a technology called thin film, in which the silicon material is spread in fine layers on such materials as glass. But the new technique takes low-grade silicon and, in the process of increasing its purity, forms it into tiny, separate spheres, each capable of producing electricity. These are embedded in a heavy aluminum foil that has been re-formed into mesh--something like a fine window screen. More than 17,000 of these spheres are used in a 4-inch-by-4-inch square, which resembles sandpaper but has roughly the equivalent electricity-producing capacity of conventional solar cells.
