India’s solar manufacturing sector is expanding unevenly, with module production scaling rapidly while cell manufacturing continues to lag. Despite policy support and strong domestic demand, the gap highlights underlying technology and market constraints.

Module manufacturing benefits from simpler assembly processes and lower capital requirements, but cell production remains capital-intensive and technology-driven, requiring advanced infrastructure and continuous upgrades. This disparity is influencing investment trends and the long-term competitiveness, widening the gap between India’s module and cell manufacturing capacity.

While module manufacturing capacity has expanded rapidly, ongoing advances in solar cell technology are driving frequent changes in design and production standards, prompting manufacturers to recalibrate operations. This continual evolution is temporarily limiting the effective module output as companies adapt to newer, more efficient cell technologies.

Manufacturing Differences

Understanding the differences between cell and module manufacturing is essential to assessing the solar industry’s production processes, investment requirements, and technological capabilities.

Gagan Chanana, Joint Managing Director and Chief Executive Officer at Jakson Solar Modules and Cell Business, said, “Cell manufacturing involves highly controlled processes such as chemical vapor deposition, diffusion, doping, and surface passivation, typically performed in cleanroom environments with specialized equipment. Module manufacturing, in contrast, is primarily an automated assembly process. Once the cells are produced, the focus shifts to electrically interconnecting them, encapsulating them within protective materials, and ensuring the finished module can operate reliably in outdoor conditions for decades.”

Module manufacturing has expanded in scale. India added nearly 119 GW of solar modules and over 9 GW of solar cell capacity in 2025, according to Mercom India’s State of Solar PV Manufacturing in India 2026 report.

Commenting on the difference between cell and module manufacturing, Avinash Hiranandani, Vice Chairman and President at RenewSys India, said, “Module manufacturing has its own statistical and automation requirements, but the cell manufacturing operates at a different level. A cell line must run continuously, with zero liquid discharge, even with affluent treatment control, and involves extensive statistical processes to improve average efficiency.”

The machines used in cell manufacturing operate at very high temperatures, reaching up to 800 degrees Celsius and beyond, and are fundamentally different. Module manufacturing, in comparison, is less technology-intensive than cell manufacturing.

“Solar cell manufacturing requires semiconductor-grade tools, deposition equipment, diffusion furnaces, laser systems, advanced metallization, and extensive cleanroom infrastructure. Module manufacturing, by comparison, relies mainly on automated assembly equipment such as stringers, laminators, framing systems, and testing stations, which require significantly simpler infrastructure,” noted Chanana.

High Capital Cost

Module manufacturing is largely driven by scale and competitive bidding, resulting in relatively lower but more stable margins. This stability stems from lower capital requirements compared to cell manufacturing, standardized production processes, and the flexibility to source cells from multiple suppliers. This has been the key driver behind the scaling of module production in the country, while cell manufacturing continues to lag.

Additionally, manufacturers can manage cost pressures through strategic procurement and operational efficiencies. In contrast, solar cell manufacturing is more complex and capital-intensive, with higher investment and operating costs along with greater technology risk due to the evolving nature of cell technologies.

Chanana noted that building a solar cell production line typically requires 4-5 times higher capital than a module assembly plant of similar capacity.

Prashant Mathur, Chief Executive Officer at Saatvik Green Energy, noted, “When building a cell line, manufacturers are making a long-term commitment to a specific technology-PERC, TOPCon, or HJT, each requiring distinct equipment, specialized engineering expertise, and significantly higher capital investment per GW compared to module assembly. Module manufacturing, by comparison, offers greater flexibility. It is easier to localize, adapt, and scale in response to market demand.”

Technology Upgrades

As technology continues to evolve, cell manufacturers face an uphill task in keeping pace with these changes and scaling up their production lines. While some technology upgrades may require a complete overhaul of the cell line, others are relatively simpler.

Upgrading a cell line and transitioning from one technology to another are challenging and require significant capital, making them economically unviable for many manufacturers at present. This has led to significant reliance on imports, particularly from China, which has established a strong presence in cell manufacturing.

In 2018, Mono PERC was introduced, and TOPCon entered the Indian market by 2022. By 2025, the market shifted to approximately 70% TOPCon and 25% Mono. . Although both technologies use similar manufacturing processes, TOPCon offers higher efficiency. Currently, TOPCon is in high demand in both the Indian and global markets.

“Moving from PERC to TOPCon is largely similar. It’s just the busbar. You need to modify some parts of your stringing line, but everything else remains the same. However, HJT requires different types of machines. Therefore, upgrading from PERC or TOPCon to HJT is a significant change for cell lines. The machines are different, so you can’t switch a TOPCon machine to HJT unless it is designed to support both,” Hiranandani noted.

Technology is evolving rapidly, and it takes significant capital and a skilled workforce to keep pace with the ever-changing solar landscape.

Speaking about the cost differences between upgrading cell and module lines, Hiranandani said that in modules, if technology changes, only one or two machines need to be replaced, whereas even a minor modification in the cell line would require $200,000 to $300,000. Even if the cell size or thickness changes, multiple modifications would be required, costing far more than a module line upgrade.

Module manufacturing lines are more flexible when it comes to upgrades. Changes often involve adapting equipment to handle larger wafer formats or recalibrating automated systems to support designs such as half-cut or bifacial modules. These adjustments usually involve software updates and tooling changes rather than major infrastructure modifications.

Kalpesh Kalthia, Executive Director-Business Development at Kosol Energie, said, “During the ramp-up phase, cell manufacturers often face challenges in stabilizing production yields, reducing defects, and fine-tuning process parameters for new technologies. The dependence on imported machinery and raw materials further complicates integration, and it typically takes several months to achieve consistent, optimal output levels. At the same time, cell manufacturing lines need to operate continuously to maintain efficiency, which creates additional pressure to ensure steady demand.”

Cell Technology Limiting Effective Module Manufacturing Output

Cell manufacturing, especially for advanced technologies like TOPCon and HJT, requires significantly higher capital investment, technical expertise, process precision, and strong supply chain integration, including access to wafers and upstream materials.

“The ever-evolving solar cell technology is temporarily limiting effective domestic module manufacturing output, even as installed capacity grows. Frequent technology shifts (from PERC to TOPCon to HJT) force manufacturers to upgrade lines, pause production, or operate below nameplate capacity during transitions. Longer ramp-up periods for advanced cells reduce near-term usable output due to yield learning and reliability validation. Additionally, higher sensitivity to wafer quality and process control lowers early yields compared to older technologies,” noted a top executive from a leading cell manufacturer.

Currently, module wattage output is in the 550 Wp-560 Wp range. Initial ramp-up and stabilization of cell plants have led to lower cell wattage, resulting in lower module wattage.

“Module capacities range 540 Wp-550 Wp for mono PERC and 585 Wp-590 Wp for M10 TOPCon. The range of ~550 Wp-560 Wp for today’s mainstream utility-scale silicon modules is not accidental. It reflects a convergence of physical limits, electrical constraints, reliability considerations, and system-level compatibility trade-offs,” the top executive added.

Balachander Krishnan, Chief Operating Officer at Indosol Solar, observed that multiple factors contribute to low module wattage output.

He noted that TOPCon cells use silver paste with aluminum and glass frit for metallization, which is highly moisture-reactive. Under damp-heat conditions, this can lead to severe corrosion, increased internal resistance, and, in some cases, significant power degradation ranging from 4% to 65% in experimental tests.

“TOPCon modules have shown vulnerability to potential-induced degradation, particularly during initial stages of operation. While cell-level efficiency is high, converting that into module power is challenging. Also, to maximize efficiency and reduce costs, manufacturers are using thinner glass. However, this has led to increased failures during stringent mechanical testing (e.g., hail resistance),” Krishnan added.

While the 182 mm (M10) wafer-based modules generally fall within the 550 Wp-570 Wp range, the industry is increasingly moving to rectangular cell formats (e.g., 182 x 210mm) and 16+ busbar configurations to overcome these limitations and push into the 580 Wp-600 Wp range.

Explaining the bottlenecks preventing modules from exceeding the current 550 Wp-560 Wp range, Kalthia noted that increasing wafer size or module dimensions beyond a certain point leads to higher resistive losses, thermal issues, and handling challenges, which limit overall performance gains.

“In addition, interconnection losses and reliability concerns at higher power densities further limit progress unless more advanced cell technologies are introduced. In this scenario, optimizing the bill of materials to minimize cell-to-module losses becomes critical,” he added.

Rapid advancements in technology are creating both opportunities and challenges for cell manufacturers, as continuous upgrades are necessary to remain competitive. While new technologies improve efficiency and long-term performance, frequent transitions can disrupt production, require additional investment, and affect short-term output stability.

This mismatch is gradually narrowing as policy incentives, such as the production-linked incentive (PLI) program and domestic content requirements, push manufacturers toward backward integration, but technological complexity remains a key constraint to developing a fully integrated domestic solar manufacturing ecosystem.