A Moore’s Law for Solar

Several people (myself included) have posited that alternative energy won’t likelyhave its own Moore’s Law, the phenomenon in the chip market that letsthings get cheaper, smaller and better over time.

It looks like the critics might be wrong.

Charlie Gay, the president of Applied Solar, the solar arm ofsemiconductor-equipment-maker Applied Materials, says solar panelmakers are experiencing steady cost reductions by making solar panelssteadily thinner. Manufacturers can’t reduce the X and Y dimensions ofthe solar cell easily – that would reduce the surface area exposed tothe sun, which in turn would reduce the power that a given panel couldproduce.

moores law.preview A Moore’s Law for Solar

But by producing thinner wafers, the amount of raw material gets reduced without reducing performance.

"The Moore’s Law for solar is that as time goes by, things getthinner and still absorb light," he said during a tour of Building 21at Applied, where the company conducts testing and research on itsequipment. (Gay will be speaking at Intersolar U.S. taking place in SanFrancisco next week. Our video interview with him will appear onIntersolar TV and on the Greentech Media site next week.)

The latest amorphous silicon solar modules made on Applied’s SunFabline, for instance, contain some layers measuring 100 angstroms thick,or about 30 atoms. These sheets of motherglass are 61 square feet insize.

"That is 30 atoms uniformly deposited from one side to the other," he said.

The difference between chips and solar panels, however, comes in howthese improvements are implemented. In the semiconductor world,companies shift from one manufacturing node to a more advanced oneapproximately every two years. "Solar in a sense is more analog. Itcontinues to improve over time," he said.

Gay also defended amorphous silicon. Applied primarily makesequipment for makers of silicon crystalline and amorphous crystallinesolar panels, and it is particularly interested in promoting amorphoussilicon. Several analysts assert that the future for thin film will be dominated by cadmium telluride and copper indium gallium selenide (CIGS) panels, both of which potentially will provide higher efficiencies than amorphous silicon.

Amorphous, however, is gaining in efficiency, he noted. Someamorphous manufacturers employing Applied’s machines can achieve moduleefficiencies of 8 percent.

Just as important, the manufacturing tools are more standardized, henoted. Makers of other types of thin film panels often have tocustomize their equipment.

"The question is: What is the technology that can scale?" he said.