India must strengthen its domestic bill-of-materials (BoM) and balance-of-system (BoS) manufacturing ecosystem to capture more value across the solar supply chain, panelists said at the Mercom India Renewables Summit 2026.

At the session “Solar BoM & BoS Manufacturing: Expanding Value Creation Across the Solar Supply Chain,” panelists discussed the growth of domestic manufacturing for solar glass, junction boxes, busbars, aluminum frames, interconnects, inverters, mounting structures, and other critical components.

The session was moderated by Priya Sanjay, Managing Director at Mercom India, and featured Bhupendra Singh Rawat, CEO at DhaSh Green Energy; Ruchi Kukreja, Head-Advocacy at Hindalco Industries; and Varun Gupta, Director at Triveni Renewables. The session deliberated on  domestic BoM and BoS manufacturing, investment trends, technology competitiveness, supply chain resilience, and policy support.

Sanjay said the inverter market is expected to remain strong as solar installations expand across utility-scale and rooftop segments. She noted that central inverter supply grew 48% year-over-year, while string inverter supply grew 34%. Demand for module mounting structures is also expected to remain strong, with supply volumes projected to rise 29% year-over-year.

Rawat said ancillary manufacturing is now central to India’s solar manufacturing ambitions.

“Manufacturing is the core, and ancillary is a must,” Rawat said. “Ancillary manufacturing is almost 50% of the bill of material cost of a solar module.”

He said India has already built strong domestic capacity in several components, including junction boxes, cables, and interconnects, but policy support and quality enforcement will be critical to sustain growth.

Gupta said solar glass prices must be viewed in the context of global overcapacity and market correction. He said China expanded solar glass capacity sharply between 2021 and 2023, creating excess supply that later forced furnace shutdowns.

“When you say high, it means compared to what?” Gupta said. “Between 2021 and 2023, China went from 65,000-70,000 tons per day of solar glass to about 160,000 tons per day without the underlying increase in demand.”

He said China’s solar glass capacity has since declined, but the supply-demand balance is still adjusting. New glass capacity in India will also take time to come online.

“From ground zero to glass production, it takes a minimum of 26 months, even longer,” Gupta said. “The impact of duties, which came in December 2024, will start coming by the end of this year or early next year.”

Gupta said manufacturers need long-term visibility rather than reactive trade measures against individual countries.

“We cannot be just going from antidumping duty from one country to another,” he said. “At current prices, it takes five years for a payback. We need long-term policy visibility on the lines of ALMM, which gives the industry and investors’ confidence.”

Kukreja said developers and manufacturers must build stronger supplier relationships as demand for aluminum, copper, and other materials rises across the solar, electric-vehicle, and data-center sectors.

She said companies should move away from transactional sourcing and identify strategic suppliers that can provide quality, resilience through market cycles, and technical expertise.

“All manufacturers and developers have to focus on who can be a potential strategic supplier who can actually make them grow,” Kukreja said. “The supplier should be able to provide good quality products, be resilient to market cycles, and have technical expertise.”

Panelists said technical requirements are changing rapidly as modules become larger, thinner, and increasingly bifacial.

Gupta said solar glass specifications have changed significantly over the last five to seven years, especially after the COVID-19 pandemic.

“What has changed is thinner glasses, bigger sizes, and bifacial modules, which require the back glass to have holes and printing,” Gupta said. “Thicknesses have gone down from 3.2 mm to 2 mm, and manufacturers need to handle sizes up to 2.5 meters in length and 1.5 meters in width.”

However, he cautioned that module makers must carefully balance weight reduction with durability.

“While thinner glass makes the module lighter, a thicker glass definitely has more strength, ” Gupta said.

Rawat said manufacturers are also innovating in interconnects and busbars to improve module performance and reliability.

“We have offerings of reflective busbar, which also gives a little addition of output in the module,” he said.

He added that material selection is critical, especially for copper purity and alloy composition.

“The right selection is very critical-the alloy you are going to use, other than copper purity,” Rawat said. “You need to have a specific range of phosphorus, which plays a very critical role when you are doing soldering. This reduces oxidation, improves solderability, and improves overall solder strength.”

Gupta said glass manufacturing is highly energy-intensive, with gas and electricity accounting for about 40% of input costs. “That is absolutely critical “Countries like China subsidize gas or electricity. What I would want is for gas to come under GST, which could really help the industry.”

He also called for better hedging mechanisms for gas prices, saying Indian manufacturers have limited tools to protect themselves from international volatility.

“Indexes like Brent or Henry Hub are not available in the Indian market in a liquid way,” Gupta said. “It is almost impossible for individual companies like us to hedge outside the country due to RBI regulations.”

Rawat called for stronger enforcement of Bureau of Indian Standards (BIS) requirements for DC cables and junction boxes.

“Currently, junction boxes or DC cables already have BIS, although it is still not implemented,” he said. “DC cables are imported in the form of junction boxes, and it is happening freely even though BIS was announced way back in August 2023.”

He said BIS should apply to the junction box, including the cable, connector, and related components, since testing labs are available in India and only accreditation is pending.

Gupta said the solar glass industry is not seeking production-linked incentives but requires policy certainty and vigilance against duty circumvention.

“We are not looking at some kind of PLI scheme,” he said. “We are looking at long-term policy stability and a level playing field.”

He also warned that Chinese companies are moving production across countries to bypass trade barriers.

“Today it is Indonesia, tomorrow it might be Cambodia, next year Kenya, or somewhere else by Chinese companies,” Gupta said.

Panelists also highlighted risks related to access to technology and upstream chemicals. Gupta said solar glass technology has been on China’s restricted technology list for several years, and Indian companies must be careful when relying on Chinese technology suppliers. The big companies in China are not selling solar glass technology to Indian companies.”

The panel noted that India has made progress in localizing solar BoM and BoS manufacturing, but sustained growth will depend on long-term demand visibility, fair pricing, quality standards, component-level policy support, and a resilient domestic supply chain.

As India scales solar deployment, panelists said strengthening these segments can reduce import dependence, improve project economics, and help position the country as a globally competitive solar manufacturing hub.