The surge in global silver prices to historic highs has brought cost management and the search for alternative materials in solar panel (photovoltaic) manufacturing to the forefront.
With silver prices trending higher again, pressure is mounting on solar manufacturers to cut costs. Experts say hybrid silver-copper solutions are expanding, but a full transition away from silver will depend on proving durability and stability at scale.
After reaching an all-time high of $121.62 per ounce on Jan. 29, silver trading in the $94–$96 range as of March has prompted industry representatives to accelerate efforts toward technical transformation.
Andreas Lorenz, head of the "Printing Technology" group at the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, said reducing silver use is technically feasible.
"From our point of view, it is technically feasible to at least drastically reduce the silver consumption by partly or completely substituting silver with other materials," Lorenz said.
"Particularly copper is a very promising alternative material as it provides a high specific conductivity (roughly comparable to silver) but is currently by a factor of ~300 less expensive than silver," he added.
However, Lorenz noted that copper brings engineering challenges, including oxidation and diffusion into silicon. He warned that copper's rapid penetration into silicon can "strongly reduce carrier lifetime, open-circuit voltage, fill factor, and overall cell efficiency."
- Pragmatic solution is use of silver-coated copper pastes
A good solution would be to use silver-coated copper pastes instead of only copper, Lorenz said.
"These pastes contain copper particles, which are protected from oxidation with a very thin layer of silver," he said, noting they can "significantly reduce silver consumption without causing adverse effects such as oxidation or diffusion of copper into the cell."
Lorenz stressed that long-term reliability remains critical, as manufacturers must guarantee module lifetimes of 25–30 years.
"While this can be tested by appropriate reliability testing methods, it is still a risk for module manufacturers which thus has to be answered very well," Lorenz said.
He noted silver-clad copper pastes are "already widely adopted for the metallization of Silicon Heterojunction solar cells."
For TOPCon cells, a dual-printing method is used in which a thin silver grid is fired first, followed by a conductive layer using low-temperature silver-clad copper paste — an approach "now adopted for industrial application by PV manufacturers," he said.
He also pointed to strong research activity on pure copper pastes and alternative materials such as nickel and aluminum to eliminate silver entirely in the long term, noting that research institutes including ISE, UNSW and ODTU GUNAM have demonstrated principal feasibility.
"The rising silver price will definitely lead to an acceleration of the development and application of copper pastes in the industrial metallization of Si-solar cells," Lorenz added.
- 'Transition likely to be gradual'
Ning Song, senior lecturer at the School of Photovoltaics and Renewable Energy Engineering at UNSW Sydney, said the shift is underway but cautious.
"In principle, replacing silver with copper in PV metallization is technically feasible and actively pursued for cost reasons. However, achieving comparable long-term reliability and manufacturing yield remains challenging," Song said.
"The transition is likely to be gradual and application-specific rather than a direct one-to-one substitution," she added.
She described the sector as being in a transitional phase, with some copper-based approaches entering early commercial use, while silver screen printing remains dominant in high-volume production.
Regarding China, Song said manufacturers are likely to prioritize stability. "Major Chinese manufacturers typically take a pragmatic, yield-driven approach. In the near term, we are more likely to see continued silver reduction and hybrid solutions, while copper technologies mature," she said, adding: "Large-scale shifts usually occur only after clear manufacturing stability is demonstrated."
"Sustained high silver prices will strengthen the economic case for copper. However, PV manufacturing typically moves cautiously due to strict reliability requirements. Any large-scale adoption of copper will depend on continued progress in manufacturing readiness and long-term reliability validation," Song said.
By Humeyra Ayaz
Anadolu Agency
energy@aa.com.tr
