Accessing materials used in solar panels may become difficult

A new report by the American Physical Society (APS) and the Materials Research Society (MRS) cautioned against stockpiling energy-critical elements (ECE) like tellurium, germanium, cadmium and more, which are used in photovoltaics.

The report, "Energy Critical Elements: Securing Materials for Emerging Technologies," comes as China, home of the world’s largest supplies of these rare-earth elements, has said it will clamp down on exports.

The move could hamper the development of electronics, solar panels, wind turbines and more. Still, the organizations warned that stockpiling almost all ECEs could stifle innovation in electronics and renewable energy industries. Some of the semiconductors used in today’s cutting-edge thin-film photovoltaics (TFPV) use ECE like indium, gallium and selenide, which means they could be impacted by the clamp-downs.

The plan expressed in the report will help the U.S. take control of its energy future, APS-MRS said in a press release announcing the report.

“No country can mine its way to ECE independence. Instead, we need to develop an integrated approach to securing supplies of these key materials,” said Robert Jaffe, Morningstar Professor of Physics at Massachusetts Institute of Technology and co-chair of the APS-MRS study group.

While no photovoltaics rely entirely on ECEs, many do contain them. And geranium is so rare, it can only be used cost effectively in high-efficiency photovoltaics. It is too rare to be used in TFPVs.

“There are other TFPV, including CIGS (copper-indium-gallium-selenide), [that] use ECEs. There is no deployable TFPV that uses only earth-abundant elements,” Jaffe said.

Their reliance on these rare-earth elements could be problematic in the future. That’s partly because solar is a newer technology.

“Most of the established technologies like fossil fuels use well-established technologies with little space for new innovation,” Jaffe said.

Regarding most ECEs, including those used for solar panels and iPods, the APS-MRS panel recommended a number of steps the U.S. can follow to improve access to them in the future.

It recommended that the U.S. stabilize its ECE supplies through a multi-faceted approach. The approach includes research into viable substitutes, enhanced recycling and gathering and publicizing information about ECE availability.

The report, however, said the U.S. should stockpile one element, helium.

“It is unique among energy-critical elements because helium is permanently lost to the atmosphere if it is not captured during natural gas extraction,” the report said.

Many ECEs have already been used in products in the U.S. By recycling and tracking their use, the U.S. could help stabilize the amount available while alternatives are found.

But so far, there’s no comprehensive recycling plan in place.

“No one knows how much have been used,” Jaffe said. “But they are certainly not enough to offset future demand.”

Pictured: A tasteless, odorless hunk of fresh Germanium, courtesy of the Chemical Education Digital Library.