A report from CMSC indicates that the sustained increase in silver prices in recent years, particularly after the significant surge in 2025, has pushed the cost share of paste materials above that of silicon materials. The substantial volatility in silver prices has a major impact on the profitability of the industrial chain, making the substitution with base metals increasingly urgent. Based on industry feedback, active progress has been made in copper-for-silver substitution through deep collaboration across the powder, paste, and cell manufacturing segments. If industrialization proceeds smoothly, all participating segments stand to gain substantial returns. Considering that technology diffusion tends to slow during cyclical troughs, innovation in paste technology may represent the critical breakthrough point for the current supply-side challenges. The main viewpoints of CMSC are as follows:
Paste is a key material in cell manufacturing, influencing cell efficiency performance. The overall structure of a solar cell is based on a large-area PN junction. Under illumination, photogenerated electrons are collected via the fine lines and busbars printed on the cell surface, then transferred through ribbons to the external circuit to perform work, thereby converting light energy into electrical energy. The front and rear busbars of the cell are formed by printing with paste, enabling current collection at the cell level. These are categorized by shape and function into fine lines and busbars. Their pattern design affects the cell's light absorption, while material formulations influence recombination performance and determine equivalent resistance. Thus, paste is crucial to the photoelectric conversion efficiency of photovoltaic cells and the performance of modules.
"Silver" has surpassed "Silicon" in cost significance, making silver reduction the largest potential area for cost reduction. Historically, silver-based systems have dominated cell pastes. Following the sharp rise in silver prices, the proportion of paste costs within the non-silicon costs of cells has surged. Taking mainstream TOPCon cells as an example, the cost per watt has jumped from approximately 6 cents to 0.1-0.2 RMB (considering silver price fluctuations), now exceeding the cost of silicon material and becoming the largest cost component of the cell. Reducing silver consumption per unit has therefore become a primary focus for cost reduction across the industrial chain.
Positive industry progress indicates potential for large-scale application. Previously, cost reduction was pursued mainly through two avenues: 1) reducing the width of fine lines, and 2) increasing the number of busbars, which allows for thinner busbars and reduced silver consumption. However, within silver-based systems, the potential for reducing paste usage is limited. This is primarily because modern cells have higher efficiency, and the paste's function is to collect current, making it difficult to sustain large, continuous reductions in the relative amount used. Consequently, partially substituting silver with lower-cost metals is a widely recognized direction for cost reduction.
The difference in resistivity between copper and silver is small. Starting in 2024, mainstream N-type TOPCon cells began exploring copper-based systems, proposing solutions including silver-coated copper and pure copper pastes. Metallization processes involve screen printing + sintering, plating, among others. Through deep collaboration among powder, paste, and cell segments, positive progress has been achieved. Combined with industry feedback, there is hope for the large-scale application of base metal substitution by 2026.
Following significant adjustments in industrial chain profits, metallization solutions may differentiate companies. Since 2023, photovoltaic industry chain prices have undergone substantial adjustments, putting pressure on most companies' operations and narrowing the substantive differences between products. Base metal substitution has become a critical step for differentiation: on one hand, due to the significant cost differences resulting from silver reduction; on the other hand, during the industry cycle trough, only some leading companies continue R&D efforts, while many second and third-tier companies fall behind. The barriers formed by technological leaps become more difficult to overcome, potentially making this the breakthrough point for the current supply-side situation.
Risk warnings include slower-than-expected industrialization progress; a significant decline in market demand; and risks associated with rapid technology diffusion.