Nearly 4 GW of wind-solar energy has been curtailed in Rajasthan since March 2025 due to delays in transmission projects and lower power demand resulting from above-normal rainfall in north India.

In March 2025, several developers in Rajasthan received notices from the regional load dispatch centres about time-block-wise curtailment of renewable energy. The curtailment, which started at 8.5% in March, rose to 51.5% by August.

Solar and wind projects were granted a ‘must-run’ status in 2021. Any curtailments can only be made for reasons of grid safety and security, and must be communicated in writing to the generators.

Highlighting the plight of developers, the National Solar Energy Federation of India (NSEFI) wrote to the Ministry of New and Renewable Energy (MNRE), stating that solar projects in Rajasthan are not being commissioned, due to 18- to 20-month delays in transmission lines.

NSEFI stated that the total general network access (GNA) capacity in Rajasthan is 14,000 MW, while ~22,500 MW is currently commissioned and approved under GNA and temporary GNA. This has resulted in a curtailment of up to 48% during peak hours.

The Federation highlighted that several key solar projects under Phase II of the renewable energy transmission system in Rajasthan (765 kV Khetri–Narela D/C line, 765 kV Bhadla II–Sikar II D/C line, and the 400 kV Narela–Maharani Bagh line) are facing curtailment due to delays in transmission infrastructure by up to two years.

The curtailment is largely for solar projects, but wind projects are being curtailed to a smaller extent.

Kartikeya Narain Sharma, Co-Founder and Chief Business Officer at Sunsure Energy, stated that while Rajasthan is most severely affected by solar curtailment, Gujarat, Maharashtra, and Tamil Nadu have also been impacted.

Developers report that curtailment can reach up to 51.5% during peak solar hours.

“The curtailment starts at 9:30 AM with 15%, rising to 51.5% during the 10:30 AM to 2:30 PM time block. The situation has been prevalent since March 28, 2025. Since the past five months, we have been promised the curtailment will stop within a month,” said a developer.

There has been curtailment in Gujarat at rates of 10% to 30% and in Maharashtra (10% to 15%).

Akshay Hiranandani, CEO of Serentica Renewables, anticipates that the curtailment will continue until December 2025.

Lower Power Demand

Developers in Rajasthan attribute the curtailment to lower power demand and delays in the transmission infrastructure required for evacuation.

Sharma stated that the extended monsoon has resulted in muted power demand.

In May, the real-time market on the Indian Energy Exchange experienced market-clearing prices plummeting to near-zero levels, due to a surge in power supply and a simultaneous decline in demand caused by unseasonal rains and thunderstorms.

The country’s energy consumption during the month decreased 1.5% year-over-year to 150.04 billion units; however, this dip was only for one month.

Hiranandani said that the curtailment is primarily being carried out on the deemed T-GNA due to the unavailability of transfer capacity after corridor allocation to the prioritized GNA.

He explained that over the past few years, GNA connectivity has expanded rapidly, driven in part by the waiver of interstate transmission system charges, which has led to congestion in the network.

“Essentially, the issue is less about generation capacity being too high and more about grid infrastructure lagging behind the rapid scaling of renewables. The gap between transmission readiness and generation growth is now becoming evident in the form of large-scale curtailment.”

Developers claim that the delay in the transmission line from Khetri (Rajasthan) to Narela (Delhi), which has been the primary driver of the curtailment, has been delayed by nearly two years. According to a project developer, the transmission line was expected to be commissioned by November 2023.

Financial Losses

Developers report that they are incurring significant losses due to the curtailment.

NSEFI, in its letter to MNRE, stated that developers have incurred losses between ₹2.3 billion (~$26.25 million) to ₹2.5 billion (~$28.53 million) for FY26 so far.

Hiranandani said that a curtailment of 1 GW for four hours a day over 10 months translates into nearly ₹3.6 billion (~$41 million) in lost revenue at a tariff of ₹3 (~$0.034)/kWh. “For capital-intensive renewable projects, where financial models are built on predictable generation, such losses are deeply damaging. They directly affect debt servicing ability, reduce investor returns, and erode overall confidence in the sector.”

A project developer told Mercom that the curtailment is resulting in revenue losses of up to 20-25%, raising concerns about insolvency if the high-level curtailment persists for another six months.

Curtailment to Continue

While developers say that the transmission issues are expected to get resolved within this year, curtailment could occur in other states once they reach Rajasthan’s installed capacity.

Sharma stated that Rajasthan is the top destination for solar energy. It evacuates a significant amount of power to Uttar Pradesh and the National Capital Region. “Rajasthan was hit this year because it is the first choice for developers. Gujarat, Karnataka, Andhra Pradesh, and Madhya Pradesh are the next choices. Once solar capacity in those states reaches Rajasthan’s scale, they too may face curtailment due to transmission issues.”

He noted that this year saw high curtailment in northern India, but the root cause is expected to be resolved within the current financial year. “In the near term, curtailment due to a lack of transmission corridors is going to be part of life in different parts of the country.”

Is BESS the Solution?

Sharma said that transmission corridors are much harder to build than renewable energy projects, and hence, BESS can aid in utilizing them fully.

He added that Rajasthan is one of the country’s largest renewable energy zones, with around 50 GW of evacuation infrastructure. “But most of the power is solar, so it is used at best for eight hours a day and can only meet 30% to 35% of power requirements. With the addition of battery energy storage systems (BESS), this utilization can extend to 16 hours. The storage system can double the utilization of transmission infrastructure.”

He added that if one compares the prices paid by distribution companies to the exchange during peak hours, with fulfillment rates of up to 20% to 25%, storage is feasible. “It can help solve both the demand-supply gap during peak hours and the underutilization of infrastructure.”

Hiranandani said that BESS can help absorb power during curtailment periods and release it when demand is high or when corridors are unconstrained. “Over time, storage will serve as a buffer against both forecast variability and transmission congestion.”

Another project developer stated that while they are looking to install BESS on a war footing, regulatory challenges are impacting its viability.

Solutions to Avoid Curtailment

Developers emphasize that the timely commissioning of transmission projects is crucial to prevent future curtailments.

Hiranandani stated that adopting dynamic line rating, which can significantly improve transmission efficiency by adjusting line capacity in real-time based on temperature and weather conditions, rather than relying on static ratings, is vital.

He also suggested deploying storage assets at substations, which will enable BESS charging during the daytime and discharging during nighttime.

Another project developer emphasized the need for a strong deterrent to prevent transmission delays and insisted on imposing heavy penalties on transmission infrastructure developers who delay projects.

Hiranandani said independent power producers have written to the authorities seeking redressal. In the absence of a timely resolution, approaching the Central Electricity Regulatory Commission for a structured compensation mechanism will be the logical next step.

In its letter, NSEFI has also urged the government to expedite the implementation of critical transmission system components and build strategic transmission projects under the regulated tariff mechanism.

It also requested that the government establish a comprehensive compensation mechanism for developers to mitigate revenue losses resulting from involuntary curtailment.  The compensation could include providing funds to compensate developers, installing BESS to utilize curtailed power, and facilitating market sales. It also suggested providing viability gap funding for the installation of BESS in substations experiencing congestion.

NSEFI wants the government to incorporate modifications into future power purchase agreement conditions to account for the non-availability of GNA as a ‘change in law’ event.