Suniva News Just Keeps Getting Better
Greentech Media
Silicon solar cell startup Sunivais on its way to triple its manufacturing capacity, which would enableit to better compete with competitors with much larger factories. The Norcross, Ga., company has begun production at its new 64-megawatt line. The company began commercial production on a 32-megawatt line last October.
Suniva’s technology grew out of research by Ajeet Rohatgi at theGeorgia Institute of Technology. Rohatgi founded the company and setout to commercialize a process to make cheaper monocrystalline siliconcells. The company makes cells and sells them to companies thatassemble the cells into panels.
Crossing the 100-megawatt capacity would be crucial for any startupcompany wishing to compete with large competitors in the United States,Europe and Asia — and they are many. The larger you are, the moreeasily you are able to shave manufacturing costs.
Besides announcing a manufacturing expansion, Suniva also saidWednesday that solar cells coming off its production line, brandedARTisun, could convert "more than 18 percent" of the sunlight thatstrikes them into electricity.
Back in September, the company said its cells made with the ARTisuntechnology in its lab could achieve 18.5 percent efficiency. Suniva’sresearchers also were able to fabricate other cells that could achieveroughly 20 percent efficiency, a claim verified by the NationalRenewable Energy Laboratory.
Lab-made cells tend to have higher efficiencies than what can beachieved in a factory, where the process of producing cells in highvolumes could cause snafus that affect the quality of the products.
Improving the efficiency of its commercial cells is important forSuniva deliver on its claim that it could make highly efficient cellsat low production costs, which would lead to cheaper electricity. Thecompany hasn’t disclosed its manufacturing costs.
The new efficiency number for its commercial cells also puts Sunivain a club of companies that are producing more efficient silicon cellsthan most.
Suntech Power, for example, is using a new process it calls Pluto that has produced commercial cells with 18.8 percent efficiency. The Fraunhofer Institute for Solar Energy Systems in Germany verified the efficiency claim.
SunPower, meanwhile, has been producing monocrystalline siliconcells with a little over 22 percent efficiency for about two years now.The company’s panel holds a world record (20.3 percent),
Suniva is using a conventional screen printing methodfor making the metal contact lines on the front of the cells, unlikeSunPower and Suntech, said Suniva’s spokesman David Briggs. Contactlines are metal, typically silver, that transport electricity generatedfrom each cell.
The conventional method is cheaper than fancier processes and hasbeen around for decades. But it poses limitations that make it moredifficult to improve efficiencies, which hover in the mid-teens.Figuring out a way to gain efficiencies while using screen printingenables Suniva to make higher performing cells with a low-cost method.
SunPower also uses screen printing, said spokeswoman Helen Kendrick. But the company has an unusual approach of creating the contact lines on the back of the cells, and that frees up space on the front of the cells to trap more light.
Suntech’s Pluto technology does make use of screen printing, but notthe conventional kind, said Martin Green, a professor at the Universityof New South Wales whose research led to the Pluto technology. Greenled the team that created the world’s most efficient silicon cell (25percent), according to Progress in Photovoltaics, a scientific journalthat keeps track of efficiencies achieved by companies and researchinstitutions.
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