The indium market's focus might be tuned to liquid crystal displays (LCDs) currently, but analysts see the solar industry as a major bright spot in driving future recycling needs.
An anticipated growth in demand for solar semiconductors made from copper, indium, gallium, (di)selenide (CIGS) material is expected to drive increasing use of indium, leading to an increased focus on improving indium recycling methods for solar semiconductors.
The market is divided primarily into two segments silicon wafers and thin-film transistors (TFTs). Silicon-wafer-based solar semiconductors represent more than 90 percent of the market, understandable given their ability to more efficiently harvest light with a 20-percent photon conversion rate.
Indium is used primarily in CIGS in the solar industry, with TFTs accounting for only a sliver of the market. With a conversion efficiency rate of 10 percent, CIGS has a significant amount of ground to make up before it can be viewed as competitive. However, advocates argue that CIGS can be as efficient as silicon, having achieved more than 15 percent efficiency in laboratory tests. With further improvements, analysts believe CIGS could emerge as a strong competitor to silicon and drive demand for indium.
As primary sources of indium continue to be at the mercy of the weak zinc market, the steady stream of supply offered by recycled indium has kept prices from spiraling out of control.
"As far as where does indium come from in five years, I can only tell you that the recycling capacity of indium must increase," said Douglas Hunter, a trader at London-based physical trader Wogen Plc. Indium prices could soar if recycling remains at current levels while the expected growth in the CIGS industry starts to compete more heavily with the LCD industry.
Hunter estimates CIGS industry demand for indium will reach between 110 and 120 tons annually by 2011, more than five times the 21 tons of consumption in 2007 reported by Cranston, R.I.-based alloyer AIM Specialty Materials USA. Still, these figures pale compared with AIM's forecast of 2,193 tons of indium-tin oxide consumption in 2009. Indium-tin oxide is a compound used in TFT LCDs.
SolarVision Consulting, a Silicon Valley, Calif.-based company, said that a single CIGS solar panel would need approximately 4 grams of indium vs. only a few fractions of a gram used in LCD panels. Naturally, there's also a cost component to recycling vs. disposal, but "at least now it makes some financial sense," SolarVision founder Andy Skumanich said. The company estimates the cost for in-house recycling of elements in CIGS TFTs at about 5 cents per watt compared with $3 per watt to make a solar panel.
The development of CIGS recycling has taken place largely in Europe, where it is moderately advanced, Skumanich said. The European Electronic Recyclers Association in the Netherlands already has targets for recycling materials such as TFTs. Market observers agree that the U.S. is missing an important market opportunity by not building up infrastructure for CIGS recycling.
Recapture Metals Ltd., a gallium refiner based in Peterborough, Ontario, is an exception, having developed a CIGS recycling process that can separate indium from gallium, a challenge that few companies have mastered.
"I would say that people who are recycling indium at the moment can look forward to a relatively stable business in the next couple of years at least," Hunter said.
Some analysts disagree, though, saying CIGS won't be a viable competitor in the solar industry. Jack Lifton, a Detroit-based strategic metals consultant, strongly believes that CIGS won't succeed because the key minor metals used—indium, gallium and selenium—are all byproducts of other base metals and thus subject to fluctuations in these markets.
While the CIGS market has yet to prove itself as a significant commercial threat to silicon-based wafers, analysts generally agree that if the technology can be successfully transferred from lab to fabrication, indium demand will rise, which bodes well for the recycling segment of the industry.
Overall, CIGS recycling and end-of-life solar panel recycling remain in their infancy in terms of scrap generation, but should CIGS take off then recycling's role could become a major factor.