Copper's Oxidation Dilemma: Can Solar Makers Overcome the Durability Challenge as They Ditch Silver?

The global solar industry faces an unprecedented materials crisis. Silver prices have skyrocketed to an all-time high of $93.77 per troy ounce in mid-January 2025, forcing manufacturers to rapidly pivot toward alternative materials. While copper emerges as the most promising substitute, a critical question looms: how long does it take for copper to oxidize, and can this oxidation timeline allow for reliable, long-term solar installations? The answer to these questions will shape the industry’s technological trajectory for years to come.

According to Bloomberg NEF’s September 2025 report, silver now accounts for roughly 14 percent of total solar panel production costs—a dramatic spike from just 5 percent in 2023. At that earlier point, silver traded between $42 and $46 per ounce. The price explosion, nearly 200 percent higher than the year before, has created an untenable situation for manufacturers operating on razor-thin margins. In response, major Chinese solar producers are rushing to adopt base metals and innovative technologies to manage input costs and maintain competitiveness.

The Silver Crisis Driving PV Manufacturers to Copper-Based Solutions

China dominates global photovoltaic manufacturing, controlling more than 80 percent of worldwide production capacity across the entire supply chain—from polysilicon extraction to finished modules. This concentration has allowed Chinese firms to lead the charge in developing copper alternatives. In January 2025, Bloomberg reported that LONGi Green Energy Technology (SHA:601012), one of the sector’s technological leaders, would launch mass production of silver-free solar cells in Q2. The move signals a structural shift in industry strategy rather than an isolated corporate decision.

JinkoSolar Holding (NYSE:JKS), the US-listed Chinese manufacturer, announced similar intentions in December 2024, pledging to scale up production of solar panels using base metals. Meanwhile, Shanghai Aiko Solar Energy (SHA:600732) has already begun producing 6.5 gigawatts of solar cells without any silver content. Antonio Di Giacomo, senior market analyst at XS.com, notes that this convergence of effort among industry leaders reflects a fundamental redesign of how solar panels are manufactured and assembled.

The transition represents far more than cost-cutting. As Di Giacomo explains, “The exponential growth of solar energy has turned the sector into one of the largest industrial consumers of silver, intensifying competition with other strategic uses such as electronics and investment. This imbalance between supply and demand has pushed costs higher and squeezed margins for solar module manufacturers.”

Copper Oxidation: The Timeline and Technical Barriers to Solar Adoption

Copper emerges as the natural candidate to replace silver in solar cell metallization. The red metal costs far less and benefits from a diversified, robust supply chain. Currently, a troy ounce of copper trades at approximately 1/22,000th the price of silver, creating enormous economic incentives for the substitution. Yet this advantage comes with significant technical liabilities.

Unlike silver, copper exhibits natural oxidation tendencies, particularly when exposed to heat, moisture, and extended UV exposure. The oxidation timeline presents a genuine engineering challenge. Copper oxide forms relatively quickly under fabrication conditions—accelerating further during thermal processing at the high temperatures required for tunnel oxide passivated contact (TOPCon) cells, the technology currently dominating the industry. This oxidation degrades copper’s electrical conductivity and compromises long-term reliability, potentially reducing the lifespan and efficiency of solar modules over their 25-30 year operational window.

“Although its conductivity is slightly lower, copper is far more abundant, cheaper and supported by a more diversified supply chain,” Di Giacomo states. “These characteristics make it an attractive option for an industry seeking to scale production without exposure to bottlenecks in critical raw materials. However, the durability question remains unresolved.”

The oxidation challenge proves less problematic for back-contact (BC) cell technology, which operates at lower processing temperatures compared to TOPCon architecture. This technical distinction is crucial: LONGi and other manufacturers pursuing BC cells face fewer implementation hurdles related to copper oxidation timelines. Research from renewable energy advisory firm Rinnovabili indicates that BC modules can generate up to 11 percent more power over their operational lifetime than TOPCon cells, while simultaneously simplifying copper integration.

How Long Does Copper Last? The Performance Question

Recent advances in copper metallization offer growing optimism. New generations of copper-metallized cells are approaching the efficiency levels of traditional silver-based designs. In some cases, manufacturers report improvements in mechanical strength and module durability—factors critical for long-term performance in demanding environmental conditions.

Field testing data suggests that engineers are successfully extending copper’s operational window through advanced passivation techniques, protective coatings, and modified processing parameters. These innovations are steadily reducing the oxidation risk that initially made copper seem impractical. The convergence of these improvements suggests that copper can deliver the 25+ year lifespan expected from commercial solar installations, provided manufacturers implement proper mitigation strategies.

Market Implications: When Will Copper Replace Silver Across the Solar Industry?

The Silver Institute reported in November 2025 that industrial silver demand is projected to decline by 2 percent in 2025 to 665 million ounces. Notably, solar industry demand for silver alone is expected to drop approximately 5 percent, even as global PV installations hit record-breaking volumes. This decline reflects the “sharp drop in the amount of silver used in each module,” according to the institution’s analysis.

“A sustained reduction in solar sector silver demand could fundamentally alter market dynamics,” cautions Di Giacomo. However, the transition won’t happen overnight. Molly Morgan, senior research analyst at CRU Group, notes that TOPCon technology is projected to capture roughly 70 percent of the market through 2026. Manufacturing costs for BC cells—the technology best suited for copper integration—won’t reach parity with TOPCon production until the end of the decade.

This timeline creates a window for technology coexistence. “We might see both technologies operating in parallel through the 2028 to 2030 period,” Morgan explained. During this transition era, silver will remain critical for established production lines, while copper-based systems gradually prove their long-term reliability and cost advantages.

The oxidation question remains under active investigation, but early results indicate that copper can deliver acceptable durability when properly engineered. As manufacturers accumulate field data on how long copper components perform under real-world conditions, confidence in the material’s viability will likely strengthen. Within the next 2-3 years, the copper oxidation timeline challenge should shift from a fundamental barrier to a manageable engineering problem, accelerating the industry’s transition away from silver and toward more sustainable, cost-efficient materials.

The solar industry’s pivot toward copper reflects both economic necessity and technological confidence. How long copper actually lasts in field installations will ultimately determine whether this transition succeeds or requires yet another materials revolution.