China’s Longi says it will begin mass production of base metal PV modules in the second quarter of 2026, as rising silver prices increase pressure to reduce metallization costs.
Chinese module manufacturer Longi has revealed that it will begin mass production of base metal PV cells in the second quarter of 2026, with rising silver prices and cost pressures on the solar manufacturing supply chain pushing towards copper-based metallization.
The company announced in investor communications on January 5 that it has already started building some of the production capacity needed for the service. Longi described this move as a strategy to reduce metallization costs and manage raw material exposure, while maintaining the performance of the back-contact (BC) cell platform.
Longi said BC architectures are better suited to alternative metallization approaches because most of the conductive features are located at the back of the cell, reducing optical and pattern limitations compared to regular tunnel oxide passivated contact (TOPCon) designs.
Silver prices have risen sharply in recent weeks, reaching a record high of $83.62 per ounce on December 28. Solar energy production is one of the largest industrial end uses of silver, making the sector highly sensitive to price volatility.
BloombergNEF analysts have said that solar power producers are the world’s largest industrial consumers of silver and expect demand for silver from PV modules installed this year to fall to about 194 million troy ounces, or about 6,028 tonnes (MT). That would represent a 7% year-over-year decline as manufacturers accelerate their efforts to ‘economy’ and replace materials.
Longi did not disclose expected unit cost savings from copper metallization. Metallization remains one of the most expensive consumables in cell production, and replacing silver with copper could significantly reduce costs per watt if reliability and yields are maintained. The company said it has evaluated multiple approaches, including patterned vacuum coating and base metal pastes, and is now focused on integrating materials, equipment and process steps to support high-volume production.
Technical hurdles remain. Copper is more susceptible to oxidation and diffusion-related degradation, increasing the demands on barrier layers, sintering processes and long-term moist heat performance. Yield stability at scale and third-party reliability testing are expected to play a central role in determining how quickly copper-metallized cells are accepted in mainstream tenders.
Separate research by Ghent University in Belgium and Engie Laborelec, the research unit of French energy group Engie, has highlighted longer-term supply risks. The researchers estimate that total global demand for silver could reach 48,000 tons to 52,000 tons per year by 2030, while the expected supply would only reach about 34,000 tons.
The study found that silver demand in the PV sector could increase to 10,000 tons to 14,000 tons per year by 2030, driven by higher silver use in cell designs such as TOPCon and heterojunction technology. Under these scenarios, the PV industry could represent 29% to 41% of expected global silver supply by the end of the decade.
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