Fabtech: Few solar photovoltaic sectors exhibit as volatile a combination of hype and promise as the copper indium gallium (di)selenide (CIGS) thin-film segment. A handful of companies–Global Solar, Wurth, Showa Shell, for example—are already manufacturing relatively modest amounts of commercial products using CIGS (or its cousin, CIS) films on glass, stainless steel, or flexible substrates, while a larger number are just developing (or trying to develop) processes, building and characterizing (or trying to build and characterize) pilot or initial manufacturing lines, or talking (and talking) about building volume-manufacturing facilities.
CIGS companies are a mix of public and private, venture-funded start-ups and units of large corporations, relative newbies and long-time veterans. Process technologies employed by the CIGS crowd, many of which have been in R&D for decades, range from vacuum to nonvacuum, evaporation/coevaporation to sputtering, ink-print to selenization, electrochemical to RTP diffusion techniques—or combinations thereof. Some use rigid substrates, others prefer flex, some employ batch process techniques, while others take a roll-to-roll or web approach. Module integration strategies include both discrete and monolithic approaches.
The CIGS players tout common themes on the advantages of modules made with their material: The thin-film cocktail has the most conversion-efficiency upside of any non-crystalline silicon PV material (up to the high teens, though current device efficiencies are in the low double-digits and module efficiencies a few percentage points below that). The toolsets are/will be cheaper and more efficient, and the process promotes better utilization of the critical materials, especially compared to c-Si technologies. CIGS provides the best opportunity for facilitating true building-integrated PV, which will be a huge market some day, and also will be very competitive for large, utility-scale solar farms and personal/portable apps. Most importantly, the delivered cost per watt of CIGS modules produced on fully characterized, volume CIGS lines will run less than a dollar–maybe even way less—thereby achieving the ultimate goal of grid parity with the existing carbon-generating power sources.
In recent months many CIGS outfits have made a series of PR and VC moves, while others have been quiet, even downright stealthy, or at least less prone to tooting their own horn. Honda Soltec created a bit of noise in mid-November when it opened its Kumamoto production plant, which it says will have a 27.5 MW capacity when fully ramped later this year. A week later, Solibro Solar, a spinoff from Angstrom Solar in Sweden and majority controlled by number-two solar-cell maker Q-Cells, said its first factory (25-30 MWp capacity) is under construction in Thalheim, Germany, and will come online in the second half of 2008. Global Solar announced in early 2007 that its second CIGS plant (30 MW) would open near Berlin in the latter half of this year, in addition to an expansion–from 4 to 40 MW—of its core Tucson fab. Showa Shell said last summer that it plans to add a 60-MW plant next to its current 20-MW CIS line in Miyazaki….