Open access solar remains one of the fastest-growing segments in India, driven by rising commercial and industrial (C&I) demand, rising grid tariffs, supportive state policies, and the shift toward decarbonization. Growth, however, varies significantly by state due to differences in regulatory frameworks, charges, and land availability.

In the first nine months (9M) of 2025, India added 6.1 GW of solar open access capacity, a 13.4% year-over-year (YoY) increase from 5.4 GW, according to Mercom India Research. The top five states accounted for 85% of the total installations during the period.

#1 Karnataka was the leading state contributing to 27% of the overall open access solar capacity added in the country in 9M 2025, a 91% YoY growth.

Karnataka has also retained its position as India’s leading state for cumulative solar open access capacity, accounting for about 30% of the country’s total. About half of the state’s total large-scale solar capacity is installed under open access, reflecting the state’s conducive regulatory environment and strong adoption by C&I consumers.

About 45% of Karnataka’s open access pipeline consists of wind–solar hybrid power projects, followed by standalone solar (~35%) and hybrid power with battery energy storage systems (BESS) (~20%), highlighting the state’s strategic shift toward more flexible, dispatchable renewable energy solutions.

#2 Maharashtra came in second, accounting for 21% of total solar open access additions in India during 9M 2025, up 37% year-over-year.

Maharashtra also had the second-highest cumulative installed open access solar capacity, accounting for 17.3% of the country’s total. Of the state’s total installed large-scale solar projects, more than 45% are under the open access system.

The recent regulatory uncertainty in the state has led developers and C&I consumers to scale back investments due to energy banking limits, adverse time-of-day (ToD) tariffs, and open access charges. As a result, installations in Q3 2025 fell by 80% quarter-over-quarter and 43% YoY.

In November, the Bombay High Court quashed MERC’s review of the multi-year tariff order. It stayed Maharashtra State Electricity Distribution Company’s attempt to confine banked energy usage to solar hours, restoring the earlier rule allowing withdrawal in any non-peak slot. Although the ruling temporarily restored flexibility, it reinforced concerns about regulatory unpredictability.

Even with these challenges, the Maharashtra market is expected to maintain moderate momentum, supported by timely approvals from distribution companies, strong corporate sustainability commitments, and declining operating costs.

The majority of Maharashtra’s open access solar pipeline comprises standalone solar projects (86%), followed by wind-solar hybrid power projects (~13%). There could be a shift in demand for hybrid power with BESS due to the regulatory changes and market adjustments.

#3 Rajasthan took third position, representing 19% of the total open access capacity added in 9M 2025 in the country, a 5% YoY growth.

Rajasthan had the fourth-highest cumulative solar open access capacity, accounting for 11.4% of the country’s total. Open access projects comprise over 10% of the state’s cumulative large-scale solar capacity.

Rajasthan witnessed the commissioning of several interstate transmission system lines in 2024, allowing previously delayed open access projects to move forward.

New renewable energy projects connected to the state transmission utility (STU) network with an installed capacity greater than 5 MW must install energy storage systems capable of storing at least 2 hours of energy, or 5% of the project’s installed capacity.

Although this mandate increased project costs, it is supported by incentives. This includes a 75% exemption from transmission and wheeling charges for seven years and additional benefits for higher storage deployment. These measures aim to offset the additional investment burden and improve the financial viability of open access projects.

Rajasthan had the largest open access solar project pipeline in India as of September 2025, dominated by standalone solar projects (~78%), followed by wind-solar hybrid power projects (~14%) and solar with BESS (8%).

#4 Gujarat was the fourth-largest state for open access solar, contributing to 10% of the country’s total. Solar open access capacity grew by 28% from 9M 2024.

Gujarat had the third-highest cumulative solar open access capacity in India, comprising 11.8% of the country’s total. The share of open access in the state’s cumulative large-scale solar capacity was 17.4%.

Electricity tariffs in the state for C&I consumers in FY26 rose by up to 9% from the previous year, improving the cost competitiveness of open access for large power consumers. The state’s new renewable energy policy is reinforcing this shift by promoting clean energy adoption and aiming for a 50% renewable share of its power mix by 2030.

Of the state’s solar open access project pipeline, about 51% comprised standalone solar projects, and ~36% were wind-solar hybrid power projects.

#5 Tamil Nadu ranked fifth, accounting for 8% of the total open access capacity additions during 9M 2025, a 14% YoY decrease.

Tamil Nadu ranked fifth in cumulative solar open access capacity, accounting for 9.6% of the country’s total. Open access represented more than 40% of the state’s cumulative installed large-scale solar capacity.

The Tamil Nadu Electricity Regulatory Commission marginally increased the retail tariff for C&I consumers and the cross-subsidy surcharge, but the additional surcharge has been sharply reduced.

A large share of Tamil Nadu’s solar open access project pipeline comprises standalone solar projects (~61%) and wind-solar hybrid projects (~39%).