At the recent International Electronics Forum (IEF) in Dubai, UAE, I attended two days of presentations about the semiconductor industry. The speakers were from all parts of the world and offered unique perspectives. But the talk I found most interesting was given by Mark Pinto, CTO and senior vice president at Applied Materials, as his presentation tackled “Energy Conversion: Photovoltaics.”
Photovoltaics (PV) have been making great strides in the last few years, but Pinto showed just how far this technology has come. He addressed the question of whether or not it’s economical with a graph adapted from the National Renewable Energy Laboratory illustrating the learning curve of a PV module’s cost per watt. Module price was plotted on a log scale against cumulative production in megawatts since 1980, also on a log scale.
According to Pinto, module price has been coming down steadily at a rate of about 20% per year. In 1980, the biggest solar fab provided 1 MW per year of production. It took 20 years to get to a 10-MW fab, and it has taken five years to go to a 100-MW fab. And, it should only be a couple more years to get to gigawatt fabs.
Continuing the economic argument for solar power, he showed that the installed system price per kilowatt-hour (kWh) dropped to $0.30 in 2007, which is below the peak rate charged in California for mid-size installations, not including government incentives. Compare this to almost $0.70/kWh back in 1995. With new technologies like thin-film, the cost per kilowatt-hour is well below the peak rate. By 2010, it will be lower than the average rate.
Again, this is without considering how government incentives might make the economics for photovoltaics even more attractive. Pinto mentioned that over $100 billion is spent for electricity in the $0.20/kWh to $0.30/kWh range. “So you can see we’re really entering interesting territory,” he said.
DRIVING DOWN PV COST
How does the industry continue to drive down cost? As an example, Pinto showed a slide with new equipment from Applied Materials that lowers the cost per area. For waferbased technology, this means producing very thin wafers, achieving high-volume throughput—thousands of wafers per hour—and by producing big, garage-door-size substrates.
The cost equation also depends on efficiency. There are different kinds of structures, crystalline or thin-film, to maximize efficiency. But the trick is to increase efficiency without introducing higher process costs. Another fairly straightforward way to improve efficiency is to increase yield.
Finally, he put into perspective the cost of installation. “One of the other things we found as we looked at this technology trend was as you build big modules on big glass, installation costs actually go down,” he said. System integrators measure dollars per watt for the entire system.
For standard 1.1- by 1.3-m modules, there is a cost associated with clamps, rails, cabling, and labor. These costs are reduced by more than 15% by a module such as the one produced by Applied’s SunFab, which is a 2.2- by 2.6-m glass with an area of 5.72 m2.
Large substrate size may also pique the interest of architects who can use the larger modules as skylights and glass facades. If an architect chooses to incorporate solar modules into a building, their installation cost is effectively eliminated. That is, the material is being used to construct the building, so there is no after-the-fact add-on cost.
Pinto makes a great case for the economic viability of solar power. The PV industry seems to be on the cusp of a breakthrough due to better technology and larger module sizes. If this scenario sounds familiar, it is. We’ve just seen it occur over the past several years with LCDs.
DUPONT EXPANDS SOLAMET PRODUCTION
In a related story, DuPont will expand production of its Solamet thick-film metallization pastes at its Electronic Materials DuPont Dongguan Ltd. (EMDD) facility in Dongguan, China. The company will more than double its manufacturing capacity of Solamet pastes as part of its overall strategy to more than triple its sales to the PV industry.
DuPont expects that its sales into photovoltaics within the next five years will be more than $1 billion—up from about $300 million today. The company anticipates that the PV market will grow by more than 30% in each of the next several years, driving demand for existing and new materials that are more cost-effective.
“The PV industry is in the midst of a substantial surge globally, and demand for solar as a renewable energy source will continue to increase,” said Timothy P. McCann, VP and GM, DuPont Electronic Technologies. “We are expanding Solamet production to support increased demand. Through future development, we will accelerate our ability to deliver innovations that will further drive down PV system costs and improve the lifetime and performance of solar modules.”
Solamet thick-film metallization pastes are used for frontside and back-side metallization of solar cells, enabling solarcell manufacturers to significantly reduce their cost per watt by achieving higher cell efficiencies, higher production yields, and lower material consumption.