Getting CIGS solar panels to market is turning out to be a little tougher than expected.
Some companies that hope to make thin, inexpensive solar cells out of copper indium gallium selenide, or CIGS, have had to delay commercial production of their products or change their product line.
"We're trying to give birth to a new process. The trouble is that we don't know how long the gestation period is," said Dave Pearce, CEO of Miasole, which has received more than $56 million in venture funding and is one of the more prominent CIGS companies. "But nothing has changed in terms of the fundamentals of the technology."
The snags largely arise, the companies say, from the difficulties of bringing a new technology to market.
In the solar world, there's a major battle brewing between makers of silicon solar panels and those who want to produce CIGS panels. Commercial crystalline silicon solar panels--the kind seen on rooftops--can convert between 15 percent and 22 percent of the sunlight that strikes them into electricity.
Even the best CIGS panels are below that. CIGS backers, however, say their cells will be cheaper. A shortage of solar-grade silicon that started in 2004 has caused manufacturing prices to rise.
Silicon cell factories are also expensive and use the same sort of equipment found in LCD TV factories. By contrast, CIGS cells, in theory, can be manufactured almost like plastic wrap or foil in a roll-to-roll process.
A factory that can produce 30 megawatts worth of silicon solar panels might cost close to $100 million. CIGS manufacturers say they can build factories for $25 million that will produce their 25-megawatt panels.
Miasole's issue? The company can produce 5-square-foot sheets of CIGS solar cells that can hit the company's target efficiency of 8 percent to 10 percent on its research-and-development production lines, Pearce said. (The efficiency rating refers to how much of the sunlight the panel can convert into electricity.) However, on its commercial production lines, Miasole is seeing efficiencies of 4 percent to 6 percent, with some high spots of 9 percent mixed in.
"They aren't at the level of efficiency we want," he said. "You've got four elements (copper, indium, gallium and selenide) that do not want to be together."
Pearce said the company will likely enter into volume production in October--later than expected. In September 2006, Miasole had said it expected to achieve revenues of $100 million by the end of 2007. That probably won't happen now, Pearce added.
Not all bad news
Meanwhile, DayStar Technologies said earlier this month that it will initially produce CIGS solar cells on glass rather than on metal foils. That's a big switch: one of the major selling points of CIGS is that it can be produced on cheap, light substrates that can be incorporated into building materials. Until now, DayStar had touted its TerraFoil solar cells on a titanium-based foil.
"The market for a flexible CIGS module is viewed as a large potential market for the future. However, there still remain significant technical challenges in product packaging that inhibit early market penetration," the company stated in its first-quarter earnings release.
Not everyone is having issues. Nanosolar, which hopes to print CIGS cells, is putting out solar cells on its pilot line and will start to produce commercial volumes toward the end of the year, said CEO Martin Roscheisen. That prediction would fit the original schedule.
While the chemical formula for CIGS between different manufacturers is somewhat similar, the manufacturing processes are different. Miasole and DayStar sputter the CIGS material onto a substrate. The process is similar to the way hard-drive makers sputter magnetic particles onto disks.
By contrast, SoloPower will electroplate CIGS onto substrates in a roll-to-roll process. HelioVolt, Shell Solar and other CIGS companies, meanwhile, have their own twists on the production process. (Some also leave out the gallium and make CIS cells.)
In research labs, scientists have applied the CIGS materials in a solution and evaporated off the excess.
The production delays also reflect one of the underlying realities of alternative energy. Unlike Web 2.0 companies, these companies require massive factories, which take time and money to build. In September 2006, Pearce said Miasole would have the factory capacity installed by the end of the 2007 that would, once tuned and optimized, be capable of producing 200 megawatts worth of solar panels a year. (In 2004, Miasole said it expected to begin mass production in 2005).
The company has installed two production lines in its Santa Clara, Calif., facility that will be capable of producing a combined 50 megawatts worth of solar cells a year when fully optimized. Miasole also has ordered the parts for two more production lines.
The goal now is to hit the 200-megawatt production mark by the end of 2008.