India’s corporate solar engine broke a new record in 2025, with 7.8 GW of open access capacity added, pushing cumulative installations past the 30 GW mark — even as a deadline-driven rush distorted quarterly trends.
The annual addition was marginally higher than the 7.7 GW installed in 2024, marking the highest capacity addition ever in the segment. However, most projects were commissioned in the first half of the year, as developers accelerated execution ahead of the expiry of the ISTS charge waiver in June, leading to a sharp cooling in the final quarter.
Karnataka tops 2025 solar open access installs
Fourth-quarter additions fell to 1.6 GW, down 29% sequentially and more than 32% year-on-year, reflecting the front-loaded commissioning pattern rather than than demand weakness. According to Mercom India’s ‘Q4 & Annual 2025 Solar Open Access Market Report’, Karnataka led installations in 2025 with over a 24% share of total additions, followed by Maharashtra (20%) and Rajasthan (18%). In the fourth quarter, Maharashtra, Tamil Nadu and Gujarat together accounted for two-thirds of the new capacity.
Rising tariffs, decarbonisation fuel renewable procurement
Despite the quarterly dip, the development pipeline remains robust. More than 45 GW of solar open access projects were under development or in pre-construction as of December 2025, signalling sustained corporate appetite for renewable power procurement amid rising grid tariffs and decarbonisation mandates.
Green power trading showed mixed trends during the period. Volumes in the Green Day-Ahead Market (G-DAM) rose 18% quarter-on-quarter, with Adani Green Energy accounting for 38% of the electricity traded. Odisha emerged as the largest procurer, with a 23% share. However, Renewable Energy Certificate (REC) volumes dropped nearly 58% quarter-on-quarter, while Green Term-Ahead Market (G-TAM) trades declined 32%, highlighting volatility in short-term renewable instruments.