As Stion is ramping up commercial production at its new thin-film module facility in Hattiesburg, Miss. its production module efficiency has also increased. In fact, the commercial line has now produced a CIGS (Copper indium gallium (di)selenide) module tested at 14.8 percent aperture efficiency (13.4 percent module efficiency).
The 145-watt module was tested at the National Renewable Energy Laboratory (NREL). It’s the highest efficiency verified by NREL for a monolithically integrated CIGS module. “We sent several commercial production modules to NREL, so it’s a definitely a champion, but it’s by no means a one-off,” said Frank Yang, Stion’s vice president of business development.
As a monolithically-integrated module, Stion’s device uses a ribbon on one side of it to move all the electrons rather than a series of cells connected to a junction box. “Keep in mind not all doing CIGS are doing that. Many in the US are doing a cell approach,” Yang said.
“Certainly other companies doing CIGS have their reasons [for doing cells]. Many of those approaches have characteristics or properties that are excellent,” Yang said. “We feel our approach offers high efficiency and a scalable, reproducible process,” he said.
The company’s technology allows it to achieve high efficiencies over a large area. “What you need to do to do that is develop a stable process over a large area,” Yang said.
The results come as the company is ramping up production to 100 megawatts annually at its Mississippi facility. “We’ve started commercial shipments out of that facility and are in the process of ramping it up. We will be fully ramped or close to it by the end of the year,” Yang said.
“Today we have a stable production process in place. We’ll run something on the pilot line in San Jose when it reaches stability we’ll bring it to the commercial line,” Yang said. For now, “We’ve gotten very good average efficiency out of the factory. The average efficiency of modules coming out of the factory are well over 12 percent, closer to 13 percent, and trending upward.
Stion’s will continue to increase efficiency of the modules up to roughly 15 percent, but will first test tweaks to them at its test facility in California. Future generations of modules could be even more efficient. “We are developing second and third generation technologies that ultimately take us above 20 percent but right now we’re focussed on production results,” Yang said.