Scarce Supply of "Hitchhiker" Metals Could Hold Back Clean Technology

Indium via Wikimedia Commons/Public Domain

Many people are worried about China's control of rare earth metals that hybrid and electric cars are now dependent on, but it turns out that another class of rare metals should be demanding our concern as well.

Hitchhiker Metals Used in Green Tech
Metals known as "hitchhiker" metals, including gallium, indium and selenium, get their name because they're only available as a byproduct of the mining and refining of major metals like copper, aluminum and zinc. These metals are widely used in things like computers, LED light bulbs, solar panels and other electronics. As the demand for these products has gone up, so has the demand for the metals, but there's no easy way to expand production of something that exists as a byproduct.

At particular risk of facing a shortage of these metals is the solar panel industry. Ever heard of CIGS solar cells? The thin-film solar technology has a vast potential of uses. The letters stand for copper, indium, gallium and selenium -- three of which are hitchhiker metals. If manufacturers find these metals in short supply, all the efficiency gains and amazing applications of this technology could come to a standstill.

Beyond CIGS solar cells, indium and gallium, as well as another hitchhiker called tellurium, are commonly used across many solar technologies.

gallium crystals by foobar via Wikimedia Commons/CC BY-SA 3.0

The U.S. imported $66 million-worth of gallium, which comes from bauxite and zinc mining, in 2011, while only one company in Utah recovered and refined gallium from scrap metal and impure sources. In the case of tellurium, a metal found to be a low-cost photovoltaic material for use in thin-film panels, the supply may never meet demand as it's only available as a byproduct of copper refining.

Recycling Electronics Is Crucial
The solution will be in both the conservation and recovery of these metals. When a product containing these metals gets to the end of its life, it needs to be recycled and the metals recovered for reuse. Robert Ayres, a physicist and economist who presented this problem to the Royal Society in London told InnovationNewsDaily, "You produce something, you use it, but you don't just toss it in a landfill; it goes to another stage and another, and eventually the rare materials are recovered. At present, hardly any are recovered."

Electronics recycling is crucial for preventing pollution, protecting our health and lowering our carbon footprint, but in the case of these rare metals, it will also be important in continuing clean technology development.

The other, safer option will be to find replacements for these metals in electronics and renewable energy technologies or we risk not being able to develop and deploy solar panels just because copper refining didn't provide enough tellurium one year.

Tags: Electronics | Solar Technology