India added 26.6 GW solar PV capacity in 9M 2025, a 53.7% annual increase, the highest ever recorded, according to Mercom India Research
Large-scale projects accounted for 81.5% of new capacity, followed by open access and rooftop installations
Rajasthan, Maharashtra, and Gujarat led large-scale additions, contributing 76% of total capacity during Q3 2025
Tender activity and auctions fluctuated, with upcoming ALMM List-II rules raising potential project cost uncertainty, it added
India registered a 53.7% annual increase in solar PV installations, adding 26.6 GW during 9M 2025 (calendar year), its highest ever recorded, surpassing all of 2024, according to Mercom India Research.
The solid progress, say the analysts, was driven by large-scale solar, which accounted for 81.5% of the capacity commissioned during the period, followed by solar open access facilities at 28.3% and rooftop solar at 18.5%.
This includes 6.6 GW of large-scale capacity installed in Q3 2025, which expanded by 141% year-on-year (YoY) from 2.7 GW in Q3 2024, but dropped quarter-on-quarter (QoQ) from 9.7 GW in Q2 2025. The sequential drop reflects the impact of an extended monsoon in 2025, explains Mercom India Managing Director Priya Sanjay.
The trio of Rajasthan (38.2%), Maharashtra (20.2%), and Gujarat (17.7%) were the main contributors to large-scale additions during the reporting quarter. The Top 10 states were responsible for 99.3% of large-scale solar capacity additions.
In cumulative terms, India’s solar PV capacity reached 125.5 GW at the end of September 2025, with large-scale and rooftop solar accounting for 85.2% and 14.8%, respectively. Here, the leading trio changes to Rajasthan (29.5%), Gujarat (17.7%), and Karnataka (13.1%).
Mercom analysts list supply chain constraints, grid congestion, and curtailment as continued challenges for the industry. “DCR supply remains tight and expensive, though long-term visibility is improving. The GST cut provided some relief, but higher cell and module duties offset much of the gain,” stated Mercom Capital Group CEO Raj Prabhu.
The quarter also saw tender activity decline by 17.8% YoY, but rise by nearly 137.6% QoQ to 16.5 GW. Auctions dropped by 66.8% annually but rose 21.4% sequentially to 2.2 GW. Mercom said upcoming ALMM List-II rules may raise project costs, creating uncertainty in auctions. It refers to the upcoming ALMM for solar cells from June 1, 2026 (see India To Impose ALMM For Solar Cells From June 1, 2026).
As of September 2025, India had 191.9 GW of large-scale solar project pipeline and another 162.5 GW tendered and pending auctions.
Mercom expects installations to be higher in Q4 as developers strive to complete projects before the ALMM List-II deadline. However, Sanjay says the developer community wants a phased implementation of List-II until India has an adequate supply of domestically manufactured cells. Developers fear that power purchase agreements (PPAs) will be impacted by the rise in module costs.
Prabhu added, “Looking ahead to 2026, grid constraints remain the primary concern, and transmission capacity must scale rapidly to support growth at this pace.”
Mercom makes these assertions in its Q3 2025 India Solar Market Update, which can be purchased on its website.
