India Adds 3.8 GW Solar Open Access In H1 2025; Rooftop Segment Surges 158%

India added 3.8 gigawatt (GW) of solar open access capacity during the first half of calendar year 2025, marking a slight decline of over 4% compared to the 3.9 GW added during the same period in 2024, according to a new report by Mercom India.

The second quarter (Q2) of 2025 saw a significant rebound, with 2.7 GW of new open access capacity installed.

Developers expedited project commissioning in the second quarter of 2025 to beat the June deadline for the ISTS (Inter-State Transmission System) charges waiver.

To secure the waiver benefits, many of them partially commissioned their projects, the report noted.

In contrast, project execution in the first quarter faced delays as authorities struggled to issue timely connectivity approvals and expand transmission infrastructure.

In the first half of 2024, developers had accelerated installations to finish projects before the government reimposed the Approved List of Models and Manufacturers (ALMM).

Maharashtra Leads Q2 Additions

Maharashtra emerged as the leading state for solar open access capacity additions in Q2 2025, accounting for more than 30% of the new installations.

As of June 2025, India’s cumulative solar open access capacity stood at 24.6 GW.

Karnataka maintained its position as the top state in overall cumulative capacity, contributing around 24% of the total, followed by Maharashtra (18%) and Tamil Nadu (12%).

Mercom reported a strong development pipeline, with over 31 GW of solar open access projects either under development or in pre-construction stages as of June 2025.

Rooftop Solar Records 158% Year-on-Year Growth

In parallel, India’s rooftop solar segment demonstrated impressive performance, adding 2.8 GW of new capacity in H1 2025—a 158% increase compared to 1.1 GW installed in H1 2024.

Q2 2025 alone contributed 1.6 GW, a 33% rise from Q1’s 1.2 GW and an astounding 121% increase over Q2 2024’s 731 MW.

The rooftop growth was driven by multiple factors, including the clearing of delayed project registrations, faster commissioning of new systems, and upgrades to the government’s PM Suryaghar portal.

The residential segment led the way, contributing more than 74% of Q2 installations, followed by industrial (19%), commercial (6%), and government (0.5%).

India’s total cumulative rooftop solar capacity reached 16.5 GW by June 2025, with Gujarat, Maharashtra, Rajasthan, Kerala, and Uttar Pradesh emerging as top-performing states.

With both open access and rooftop segments showing resilient trends, India’s solar capacity expansion remains firmly on track.

Continued policy support, infrastructure upgrades, and streamlined approvals are expected to further drive growth in the second half of the year.

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