Rajasthan curtails 4 GW of solar capacity since March, industry incurs losses of up to Rs 250 crore

Following reports that solar output in India is being repeatedly curtailed during periods of low demand to keep the grid stable and relieve congestion in transmission lines, a Delhi-based renewable energy policy advocacy body has written to the Union Ministry of New and Renewable Energy (MNRE) to act on the issue.

Subrahmanyam Pulipaka, chief executive officer of the National Solar Energy Federation of India (NSEFI), told Down To Earth (DTE) on August 19, 2025, that delays in the commissioning of critical transmission infrastructure and congestion in existing lines were undermining the viability of renewable energy projects in Rajasthan and parts of Gujarat.

Since March, about 3-4 gigawatts (GW) of solar capacity has been curtailed in Rajasthan, causing losses to the industry of up to Rs 250 crore to date, he said.

Tamil Nadu and Gujarat have also reportedly been facing curtailment, but Pulipaka clarified, “In my records, there is zero curtailment in Tamil Nadu. As far as Gujarat is concerned, it is in sub-megawatts (MW). There is not much impact.”

Solar power curtailment is the practice of intentionally reducing the output of solar power generation, either at a specific solar farm or across a broader grid, to manage grid stability and avoid oversupply, thus protecting the grid. It happens when the amount of solar power being generated exceeds the grid’s capacity to absorb or distribute it, or when low demand or negative electricity prices make it uneconomical to send all the generated power to the grid.

According to details on the National Solar Energy Federation of India’s (NSEFI) website accessed on August 18, 2025, solar projects have faced curtailments amounting to 1,408 GW since the 2019 lockdown. The data is no longer available on the website.

However, Pulipaka later clarified that the figure of 1,408 GW cited was inaccurate. Curtailment during the 2020 lockdown amounted to around 323 million units of solar power, he said. “If I say there has been a curtailment in a 1 gigawatt plant, the entire 1 gigawatt is not curtailed; the plant is curtailed instead, and it could be only 300 MW (megawatt) or 100 MW for 15 minutes," Pulipaka said, citing an example.

“Our simple algorithm considered total plant capacity, how much was curtailed, and for how long the curtailment lasted,” he explained. The reported curtailment figure was incorrectly calculated as a daily cumulative of curtailed capacities over a year, which inflated the total. Actual curtailment should reflect the percentage of plant capacity curtailed and the duration, aligned with the dispatch centre's formula used by the Government of India.

The ongoing curtailment issue, he added, primarily affects new projects rather than existing ones. Pulipaka also stated that the NSEFI website is undergoing a revamp, which is why some of the figures available online may not be reliable.

In a letter to the MNRE dated July 24, 2025, a copy of which is with DTE, the federation said: “Solar projects in Rajasthan have been deferred by 18-20 months to accommodate delays in the transmission system, but are still unable to be commissioned due to even further delays.”

The letter warned that renewable energy curtailment not only results in lost revenue and underutilisation of operational capacity but also wastes valuable green energy that could otherwise support India’s sustainable energy goals. These inefficiencies, it added, jeopardise project viability and sow uncertainty among investors.

India is targeting the installation of 280 GW of solar capacity by 2030, while the current installed capacity is 119.02 GW.

Currently, Rajasthan has a general network access (GNA) capacity of 14,000 MW, while 22,500 MW has already been commissioned and approved under GNA/Temporary General Network Access (T-GNA), the NSEFI letter stated. This mismatch has forced developers to evacuate power under T-GNA margins, resulting in around 48 per cent curtailment during peak hours.

Among the critical projects facing delays of up to two years are transmission lines under Phase II of Rajasthan’s renewable energy (RE) transmission system: the 765 kV Khetri-Narela double circuit line, the 765 kV Bhadla II-Sikar II double circuit line and the 400 kV Narela-Maharani Bagh line, the letter to MNRE pointed out.

NSEFI further urged the government to expedite these projects and to take structural measures to assist developers. These steps include:

• Developing strategic transmission projects under the Regulated Tariff Mechanism

• Establishing a comprehensive compensation mechanism for developers affected by involuntary curtailment

• Using the Power Systems Development Fund to compensate producers

• Installing battery energy storage systems (BESS) to store curtailed power, with deemed approval for market sale

• Providing viability gap funding for BESS at congested substations

• Incorporating provisions in future power purchase agreements to recognise a lack of GNA as a “Change in Law” event

“We believe that taking prompt action to address transmission constraints will unlock the full potential of installed renewable energy assets, reduce energy wastage, restore investor confidence and be a major stride towards India's clean energy transition,” NSEFI wrote in its letter.

MNRE is already reviewing the matter, said Pulipaka. “We have had several meetings and commitments are now being taken from providers.”

Experts suggest addressing solar curtailment through upgraded grid infrastructure and a supportive ecosystem to ensure efficient, economical uptake of clean power.

“Solar curtailment is a serious issue considering the amount of effort and resources the country is deploying towards the expansion of RE,” said Nivit Yadav, programme director, industrial pollution at Delhi-based think tank Centre for Science and Environment. “As we plan for 500 GW by 2030, we also need to upgrade our grid infrastructure to support the energy transition. Our country needs an ecosystem that aids RE power generation and its uptake by the national grid while keeping it economical for the end user.”