Evolution of PV module BOM amid supply-demand dynamics

Over the past decade, PV technology has evolved from the parallel development of mono- and poly-crystalline, to the dominance of PERC, and now to the three-way competition among TOPCon, BC, and HJT. Each stage of innovation has also driven profound changes to the module bill of materials (BOMs), with upgrades in key materials such as glass, encapsulants, backsheets, frames, and ribbons. These shifts underscore, time and again, the BOM’s central importance in the PV industry value chain.

InfoLink’s research shows that module BOMs, after rapid capacity expansion in recent years, have faced overcapacity and a protracted market clearing process amid mounting trade barrier risks. Under the combined pressure of oversupply and rising trade frictions, how will module BoMs develop? This article explores the drivers of module BOM development via four dimensions: technology, cost reduction, efficiency improvement, and application scenarios.


 

Technology-driven: advanced packaging solutions in the n-type era

With the full transition of PV module technology into the n-type era, the BOMs for module packaging has undergone corresponding optimization.

For BC modules, insulating adhesive and solder pastes are required to ensure superior performance of welding and insulation of the BC cells. In addition, the unique string-soldering technology has driven the adoption of copper-aluminum composite ribbons.

For HJT modules, as their cells are more sensitive to UV exposure, moisture ingress, and high-temperature soldering, innovations have included UV light-transmitting encapsulants, low-temperature ribbons, and butyl sealants.

For perovskite modules, which remain in the early stages of commercialization, thermoplastic encapsulants are also under active development.

Busbar technologies are also under active exploration for both cell and modules, including the development of skin films, strip films, and UV adhesives tailored to 0BB designs. These continuous innovations and optimizations in module BOMs provide a strong foundation for technological advancement.
 

Cost-driven: accelerated grid parity in PV

Cost reduction remains the key driver for achieving global PV grid parity and accelerating the energy transition. Within the BOM, cost-down strategies are mainly realized via material adjustments, structural optimization, and thickness reduction.


 

For TOPCon glass-glass modules, encapsulation structures have evolved from the previous EPE (POE) + EPE (POE), to the current mainstream EPE + EVA, and more recently toward EVA + EVA. These transitions have gradually increased the share of EVA, thereby lowering overall BOM costs.


 

Frame materials are diversifying. New aluminum alloys, steel, and composite frames drive cost reductions and further reduce weight with thinner designs and structural optimization.


 

The thinning trend extends to encapsulants, ribbons, and glass.

The adoption of high-efficiency n-type cells, along with the application of SMBB and 0BB technologies, has driven rapid reductions in encapsulant weight and ribbon diameter.

Glass is becoming thinner to achieve module cost reduction and lightweight design.


 

Efficiency-driven: enhancement of light absorption

Efficiency gains in module BOMs are achieved mainly through two approaches.

One approach is to enhance secondary light utilization through high-reflectivity designs, including high-reflective black encapsulants, high-reflective black backsheets, and gap films, as well as high-reflective white encapsulants, high-reflective black-grid backsheets, reflective busbars, and triangular ribbons.


 

The second approach is enhancing light capture, such as improving transmittance with dual-coated glass and gradually increasing module size (corresponding BOM area) to expand the light-receiving surface. 


 

Scenario-driven: expansion of PV application boundaries

As PV capacity grows, demand for modules in specialized applications is increasing, driving BOM diversification. All-black modules are gaining share in the high-end distributed market. To further enhance aesthetics, colorless glass and black materials such as backsheets, encapsulants, frames, and busbars have been developed and adopted. Modules for harsh conditions, such as desert, offshore, and high-hail-resistance scenarios, are also key development areas.


 

 In summary, module BOMs have shifted from a single-performance focus to multi-dimensional development across technology, cost reduction, efficiency, and application scenarios. Going forward, the precision of BOM design and its impact on the auxiliary materials market will be closely monitored in InfoLink’s PV Bill of Material Market Report, offering insights into trends and market dynamics to support strategic decision-making.