“By the end of this decade, India will be a credible and competitive export origin for solar products in select global markets” 

pv magazine: Why do most Indian solar cell manufacturers continue to prioritize TOPCon rather than moving directly to back-contact technology?

Sohan Lal Agarwal: Back contact (BC) is a promising technology—nobody questions that. But there is an important distinction between a technology that shows promise and one that is commercially proven at scale. Only a handful of global manufacturers have attempted BC at meaningful volume, and the challenges around process complexity, yield stabilisation, and cost competitiveness are well documented. 

TOPCon, by contrast, is a well-understood transition. It builds on existing n-type silicon infrastructure, delivers efficiencies greater than 25.5% which is incrementally lower than that achieved in BC cells.  Although BC cells are slightly more efficient, they are also significantly more difficult and expensive to manufacture. The capital cost per GW for TOPCon is significantly lower than BC at this stage. For where India’s manufacturing ecosystem stands today, it is the right technology choice. 

There is also a broader context worth understanding. India is still building its manufacturing base. We have not yet reached the scale where we can afford to make large capital commitments on technology that has not fully stabilised globally. Regions in the far East could absorb that risk because state support meant losses were manageable. Indian manufacturers do not have that cushion—we have to be right.

When BC matures, when yields are demonstrably stable across multiple manufacturers and the cost gap with TOPCon narrows meaningfully, the transition will happen. We are designing our facilities with exactly that future insertion in mind. But capital discipline comes before technology ambition. 

At what stage do you expect BC technology to become commercially viable for large-scale manufacturing in India? 

Realistically, I would say two to three years at minimum—possibly longer. Even the most advanced global manufacturers are still navigating significant challenges with BC. It is not a technology you can install and run immediately. The process steps are fundamentally different from TOPCon, the learning curve is steep, and the global equipment ecosystem is not yet standardised the way TOPCon infrastructure is. 

Three conditions need to be in place before Indian manufacturers move seriously toward BC. Equipment costs need to come down to levels comparable with TOPCon. Yield stability needs to be demonstrated consistently across multiple manufacturers, not just one or two pioneers. And the price premium over TOPCon needs to narrow to a point where the efficiency advantage genuinely justifies the incremental investment. 

Until those conditions are met, TOPCon is where India should be investing. We are watching the global curve closely, and we will not be slow to move when the moment arrives. 

What is driving Websol’s brownfield strategy? Is speed-to-market the primary consideration? 

Speed is one part of it, but the deeper driver is capital discipline. 

When you upgrade an existing facility, you are building on a foundation that already works—the infrastructure, the utilities, the workforce, the established processes. Our TOPCon upgrade costs INR 250 to 270 crore and involves approximately 15 days of disruption to that one line, while the other continues operating normally. The efficiency of that transition is only possible because we are adding to something that is already in operation. 

A greenfield approach requires more capital, longer timelines to implement, and significantly more execution risk—and by the time a new facility reaches full utilisation, the technology landscape may have already shifted.

We funded our last solar cell manufacturing expansion, doubling capacity from 600 MW to 1.2 GW, entirely through internal accruals without raising any external capital. That financial discipline is something we take seriously. The Andhra Pradesh project will follow the same philosophy—phased, sequenced, and funded responsibly. In this business, discipline and speed are not in conflict. A brownfield approach, done well, gives you both. 

What manufacturing changes enabled Websol’s 25% reduction in silver consumption? 

This was achieved entirely through process optimisation—no new capital equipment, no technology change. The improvements came from refining paste formulations, tightening printing precision, and systematically reducing cell-to-cell variability in silver deposition. These are not headline-grabbing changes, but they reflect the kind of deep process knowledge that comes from decades on the manufacturing floor. 

Silver is one of our most significant variable cost inputs, and with prices remaining elevated, every gram saved translates directly into margin improvement. As we transition to TOPCon—which inherently consumes less silver per watt due to higher cell efficiency—the gains will compound further. The broader point is that meaningful cost improvements are available within existing technology architectures for manufacturers willing to invest the time and rigour in process excellence. We intend to keep pushing on that front. 

How has ALMM List II changed demand visibility for domestic solar cell manufacturers? 

The impact has been meaningful and structural. Previously, domestically manufactured cells were preferred in government-funded projects but not mandated. ALMM List II converts that preference into a requirement. That is a fundamentally different demand environment for manufacturers who are on the list. 

The effect is visible in our own performance. We closed FY26 with a confirmed order book of INR 1,161 crore and sustained cell utilisation above 90% through the year. The demand is genuine and growing. 

It is also worth putting the supply situation in perspective. India’s ALMM-listed module capacity stands at approximately 173 GW, while cell capacity is around 31 GW. And a significant portion of that 31 GW is not operating at full utilisation—so actual domestic cell supply reaching the market is considerably below what the installed numbers suggest. ALMM List II has ring-fenced a large and expanding portion of India’s solar market for domestic manufacturers. For those who are genuinely operational and running efficiently, this is a very favourable environment. 

Do you expect manufacturers to accelerate TOPCon expansion or delay while evaluating BC? 

I think the industry will move in two directions simultaneously. 

Manufacturers who are operationally proven, financially strong, and running their existing lines efficiently will invest in TOPCon expansion. The demand gap is real—domestic cell supply falls well short of what the market requires—and there is no commercial reason to wait. 

Those who are more likely to pause are manufacturers still working through operational challenges on their current capacity. And I think it is important to be candid about this: a meaningful sizeable number of solar manufacturing facilities in India are not yet running at the utilisation and yield levels they should be. If you have not yet mastered what you have, committing to the next technology cycle carries significant risk. 

Announced capacity and operating capacity are very different things—that is a lesson this industry has not yet fully absorbed. The companies that close that gap fastest will be the ones that define Indian solar manufacturing five years from now. 

What strategic advantages do you see in moving upstream into ingot and wafer production? 

India currently imports more than 99% of its silicon wafers. That is not a supply chain—it is a structural vulnerability. A single disruption, whether in supply availability, currency, or the export policies of source countries, exposes the entire domestic manufacturing ecosystem. 

Moving upstream, for us, is about building something that is genuinely resilient, not just commercially attractive. The Websol logic is straightforward: 30 years of cell manufacturing, forward integration into modules with our 550 MW line, and the next natural step is securing the upstream through domestic wafer and ingot production. We have signed an MOU with Linton for equipment and technology support and are targeting commissioning ahead of the ALMM List III deadline of June 2028. 

The economics reinforce the strategic case. Controlling the wafer input reduces cost variability, creates an additional margin pool within our own operations, and removes dependency on import pricing. India’s solar manufacturing will not achieve genuine global competitiveness until the full value chain—from ingot to module—is built domestically. We want to be part of building that foundation. 

What factors have driven the geographic concentration of solar manufacturing in Gujarat and Tamil Nadu, and what opportunities do you see for eastern India? 

The concentration in Gujarat and Tamil Nadu reflects genuine first-mover advantages— port infrastructure for raw material imports, land availability at scale, early state-level policy support, and the natural clustering effect where one manufacturer’s presence attracts others. Those advantages were real and they drove investment decisions logically. 

Eastern India has structural strengths that have been underappreciated for too long. West Bengal offers port connectivity, a well-established industrial ecosystem, and a technically trained workforce with deep manufacturing culture. Critically, it is the natural supply base for the eastern and northeastern states—among the most energy-underserved markets in the country—where solar deployment will accelerate significantly over the coming years. 

Websol has been in Falta, West Bengal, for 30 years. That was not a decision driven by subsidy or policy—it was a judgment about long-term industrial fundamentals. Those fundamentals are now becoming more widely understood. The geographic story of Indian solar manufacturing will look quite different in the next decade, and eastern India will be a much more prominent part of it. 

Where do you see the strongest export opportunities for Indian solar over the next five years? 

The honest starting point is that the domestic market is currently more compelling than most export opportunities. India’s solar installed capacity crossed 150 GW in FY26 and demand continues to expand. When you can sell your entire production domestically at healthy margins, the case for the complexity and risk of export markets requires a high bar to clear. 

That said, there are markets worth watching carefully. Europe’s stated intent to diversify away from Chinese supply is genuine, though whether that translates into commercial volume at prices that work for Indian manufacturers is still being tested. The United States was genuinely attractive in an earlier period, and we have established a presence there—but the policy environment, tariff structure, and localisation requirements remain uncertain enough that we are monitoring rather than committing. 

The markets I find most strategically interesting over a five-year horizon are in Africa and parts of Southeast Asia, where solar deployment is accelerating, India’s trade relationships are strong, and the preference for supply chain diversification is growing for reasons that go beyond policy. India’s cost competitiveness against Chinese manufacturing at current scale differentials is still a gap—but that gap will narrow materially as we build domestic scale and complete the full value chain from wafer to module. By the end of this decade, India will be a credible and competitive export origin for solar products in select global markets. The foundation is being laid now.