India's Solar Icarus Moment: Grid Curtailment and Storage

The Lift Line

“It’s a stellar achievement. But it is beginning to strain the country’s vast electricity grid.” (Mint)

Why This Editorial Matters for Your Exam

In the news: This reported feature by Rituraj Baruah in Mint (web headline “Is India’s solar power play facing its Icarus moment?”, online 19 October and in print 20 October 2026) argues that India’s solar build-out has run ahead of the wires and batteries that must carry it. It brings together official capacity data, an Ember analysis of curtailment, an EAC-PM working paper on the shape of daily demand, and the policy response: storage rules, contracts for difference (CfD) and market reform. Where a claim is Mint’s own reporting, we say so.

The transmission side was the subject of our earlier coverage: the Cabinet’s approval of the Green Energy Corridor Phase III on 30 September 2026, which is the background to this piece, and The Indian Express editorial on GEC-III and transmission bottlenecks. This piece adds the new angles: collapsing midday prices, the “duck and camel” shape of demand, the CEA’s draft storage rule and the CfD pilot.

GS Paper 3: infrastructure (energy); conservation and environment; Indian economy and investment models; science and technology (energy storage). Essay: energy transition and its trade-offs.

UPSC Relevance. Prelims: solar and non-fossil capacity figures, the 500 GW target, curtailment, duck curve, BESS and pumped storage, VGF, CfD, GNA and T-GNA, the role of the CEA, SECI and CERC. Mains: grid integration of renewables, transmission planning, storage policy, power-market reform and the finances of the energy transition.

Background and Context

The capacity numbers

About 35 GW of solar was added in the first nine months of 2026, close to the 38 GW added in the whole of 2025.

Key terms

• Curtailment: grid operators ask a plant to reduce or stop generation even when the sun or wind is available, because the grid cannot carry or use the power.
• Duck curve: grid operators’ name for the daily net-load profile (total load minus renewable output) of a grid with high solar: a deep midday trough and a steep evening climb. The EAC-PM paper finds India produces a “duck” in summer and a “double humped Bactrian camel” in winter, when demand peaks twice.
• GNA and T-GNA: General Network Access lets generators and buyers use the national transmission grid without a point-to-point contract; T-GNA is its temporary form.
• TRAS: Tertiary Reserve Ancillary Services. Under India’s must-run framework, inter-state renewable plants are backed down only through the emergency TRAS route, which is compensated.
• BESS and PSP: battery energy storage systems and pumped storage projects store surplus power for release when demand rises.
• Contract for difference (CfD): a generator and a buyer agree a strike price; if the market price falls below it, the buyer pays the difference, and if it rises above, the generator refunds the difference.

The Analysis

1. Capacity has outrun the wires. Ember, a global energy think tank registered in the United Kingdom, estimates in its May 2026 report that out of about 470 GWh of renewable energy curtailed across inter-state (ISTS) projects in January-March 2026, around 300 GWh was due to transmission constraints: 178 GWh in the northern region, 122 GWh in the western region and none in the south. To put the scale in context, on 30 March 2026 alone, India lost about 34 GWh, which Ember equates to the daily use of about 5 million middle-class urban households. India has met only about 80 per cent of its annual transmission targets over the past five years, and around 20 GW out of 45 GW of projects could face connection delays of more than four months. Ember puts the ISTS target for 2026-27 at about 25,146 circuit kilometres (ckm). Mint, citing CEA data, reports 4,301 ckm of lines added in April-August 2026, 58 per cent of a 7,403 ckm target.

2. Who bears the loss. Curtailment of inter-state plants under emergency TRAS is compensated. Ember notes that intra-state curtailment is “typically not compensated”, and that plants connected under T-GNA “earn no compensation when curtailed”; a 6- to 12-month connection delay can cut a project’s internal rate of return by 100 to 200 basis points. Mint reports that new auctions have slowed sharply: Icra counts about 14.7 GW of renewable capacity auctioned in FY26, against about 40 GW in FY25 and 47 GW in FY24. Icra expects renewable additions to moderate to about 40 GW in FY27, and notes that MNRE has proposed a one-time relief package to revive about 45 GW of stalled projects.

3. A glut at noon, scarcity at dusk. The EAC-PM working paper “The Duck and The Camel: Tracing the Net Load on the Indian Power Grid” (July 2026), by Sanjeev Sanyal and Satvik Dev, shows how fast demand moves within a day. For context, on 21 May 2026, peak demand met reached 270.8 GW at 3:45 pm, after 224.1 GW at 8 am: an extra 46.7 GW in under eight hours, which the paper says is more than the entire British grid drew at its peak in all of 2025. On the Indian Energy Exchange day-ahead market, the May average day went from Rs 2.81/kWh at 1 pm to Rs 8.08/kWh at 10:45 pm in 2023, and from Rs 1.11/kWh at 1 pm to Rs 9.71/kWh at 11:15 pm in 2026. The spread widened from Rs 5.27 to Rs 8.60/kWh, a 63 per cent rise, and the paper notes it would have been wider without the Rs 10/kWh price cap set by CERC from April 2023. Simarpreet Singh of Hartek Power told Mint that “instances of low or near-zero midday power prices on the exchanges are becoming more frequent”. Sanjeev Aggarwal of Hexa Climate Solutions put it plainly: “It isn’t a demand problem; it is a grid-balancing and storage problem.”

4. Storage is the missing piece. The National Electricity Plan (NEP) 2023 of the CEA projects storage needs of 82.37 GWh in 2026-27 (47.65 GWh pumped storage, 34.72 GWh battery), rising to 411.4 GWh in 2031-32 (175.18 GWh pumped storage, 236.22 GWh battery). Against that, Rubix Data Sciences counts 9.08 GWh of battery storage operational as of August 2026, with 79.92 GWh under construction, 24.13 GWh awarded and 63.53 GWh under tendering (Mint’s own count of operating capacity is lower, 8.6 GWh). Policy support so far:

• Viability Gap Funding (VGF): a scheme approved in March 2024 with an outlay of Rs 3,760 crore for 13,220 MWh, and a second scheme approved in June 2025 for 30 GWh, funded with Rs 5,400 crore from the Power System Development Fund.
• ISTS charge waiver: 100 per cent for pumped storage projects whose construction is awarded on or before 30 June 2028, and for co-located BESS commissioned on or before 30 June 2028, with conditions.
• Energy Storage Obligation: rising from 1 per cent in 2023-24 to 4 per cent by 2029-30.
• The CEA’s draft rule (3 September 2026): draft amendment regulations on technical standards for electric plants propose that ground-mounted solar and onshore wind plants commissioned after 1 July 2027 carry co-located storage of at least two hours and 10 per cent of installed capacity, rising to four hours for plants commissioned from 1 July 2029 to 30 June 2031, and that at least 15 per cent of their inverters have grid-forming control. It is a proposal, not a rule in force. Mint reports that the CEA had already advised two-hour storage of 10 per cent of capacity in future solar tenders in February 2025.

5. The market does not pay for flexibility. The EAC-PM paper notes that roughly 85 to 90 per cent of generation is supplied under long-term contracts or short-term intra-state transactions; the power exchange is “the residual layer”. A market dominated by long-term contracts gives storage and fast-ramping plants little chance to earn from the gap between noon and evening prices. Two responses are on the table:

• The draft Electricity (Amendment) Bill, 2025, released by the Ministry of Power on 9 October 2025 for public feedback, proposes that the Appropriate Commission may introduce and regulate “market products including non-transferable specific delivery contracts for difference”. It remains a draft.
• MNRE’s CfD pilot (Office Memorandum of 30 March 2026) names SECI as nodal agency for a first tender of 500 MW for 3 hours, that is 1,500 MWh of renewable power during non-solar hours.

The MNRE spokesperson told Mint that “India’s energy transition is moving from capacity addition towards delivering reliable, affordable and round-the-clock green power,” with round-the-clock, firm and dispatchable renewable energy and solar-wind hybrids integrated with storage. A CEA transmission plan of March 2026 aims to integrate more than 900 GW of non-fossil capacity by 2035-36.

Data and Institutions Vault

Prelims-grade facts:

Capacity (MNRE and PIB):

• Solar: 97.86 GW (2024) to 135.81 GW (2025), about 38 GW added in 2025.
• All non-fossil capacity added in 2025: 49.12 GW.
• Solar on 30 September 2026: 171.05 GW, about 35 GW more than at the end of 2025.
• H1 FY27 (April-September 2026): 24.56 GW renewable, 20.79 GW solar, 3.11 GW wind.
• Target: 500 GW of non-fossil capacity by 2030.
• IRENA (end-2025 data): India 3rd in total renewable capacity (ahead of Brazil), 3rd in solar, 4th in wind.

Grid and markets:

• Record peak demand met: 270.8 GW at 3:45 pm on 21 May 2026 (EAC-PM paper, July 2026).
• IEX day-ahead spread, May average day: Rs 5.27/kWh (2023) to Rs 8.60/kWh (2026); CERC price cap Rs 10/kWh since April 2023.
• Ember (May 2026): about 300 GWh of about 470 GWh ISTS curtailment in Q1 2026 due to transmission.
• Transmission targets met over five years: about 80 per cent (Ember).

Storage:

• NEP 2023 (CEA): 236.22 GWh of BESS and 411.4 GWh of total storage needed by 2031-32.
• VGF: 13,220 MWh (March 2024, Rs 3,760 crore); 30 GWh (June 2025, Rs 5,400 crore from PSDF).
• ISTS waiver for storage: up to 30 June 2028.
• Energy Storage Obligation: 1% (2023-24) to 4% (2029-30).

Law and pilots:

• Draft Electricity (Amendment) Bill, 2025: released 9 October 2025; proposes CfDs. Still a draft.
• MNRE CfD pilot: OM of 30 March 2026; SECI nodal; 500 MW x 3 hours = 1,500 MWh in non-solar hours.
• CEA draft (3 September 2026): two-hour storage at 10% of capacity for plants commissioned after 1 July 2027.

⚠️ Watch the trap: India did not add “nearly 50 GW of solar” in 2025: solar rose by about 38 GW (97.86 to 135.81 GW); 49.12 GW was all non-fossil capacity added that year. The CEA’s two-hour storage requirement is a draft proposal of 3 September 2026, and the Electricity (Amendment) Bill, 2025 is still a draft: neither is in force. Ember is a think tank registered in the United Kingdom.

The Debate

The feature’s case. India built solar faster than it built the grid, storage and markets to use it. The result is curtailed clean power, collapsing midday prices, stressed developer finances and slower auctions. The next phase must be about delivering power when it is needed, not adding gigawatts.

The other side.

• Stress is not instability. Prashant Sinha of Resonia told Mint: “However, these operational stresses should not automatically be characterized as grid instability.”
• Planning works where it is synchronised. Ember found no transmission-related curtailment in the southern region in Q1 2026, which Mint attributes to better synchronisation of generation and grid expansion.
• Low prices are a signal. A widening price spread is exactly what makes storage profitable. Aggarwal calls zero prices “a symptom of generation success running ahead of storage infrastructure”.
• Compensation exists for some. Inter-state plants backed down under emergency TRAS are compensated, which Ember says poses lower commercial risk; the exposure is concentrated in intra-state and T-GNA plants.

The balanced verdict. The problem is one of sequence, not of solar itself. Generation has been added faster than transmission (about 80 per cent of targets met) and storage (about 9 GWh operating against 236.22 GWh of battery storage needed by 2031-32). India’s tools now point the right way (Green Energy Corridor Phase III, storage VGF, the ISTS waiver, the draft co-located storage rule and the CfD pilot), but most are proposals, pilots or recent approvals. The test over the next two years is whether storage contracts and transmission lines arrive on time, and whether the draft Bill gives flexibility a market price.

How to Think About This

For any renewable-energy question, look past installed capacity to three linked questions. Can the power be carried? That is transmission, inter-state and intra-state, and connectivity (GNA, T-GNA). Can it be timed? That is storage, BESS and pumped storage, and the evening peak. Can it be paid for? That is market design: long-term PPAs, exchange prices, CfDs and who bears curtailment. A good Mains answer moves from capacity numbers to these three, names the institutions (CEA plans, CERC regulates, SECI tenders, MNRE sets policy) and keeps drafts and pilots separate from rules in force.

Diagram-in-Words

Takeaway Box

• Core idea: solar capacity (171.05 GW on 30 September 2026) has run ahead of transmission, storage and market design, so clean power is curtailed and midday prices collapse.
• Key fact: about 38 GW of solar added in 2025 (49.12 GW all non-fossil); about 300 GWh lost to transmission constraints across inter-state projects in Q1 2026 (Ember); 236.22 GWh of battery storage needed by 2031-32 (NEP 2023).
• Counterpoint: the stress is operational, not instability, and a wide price spread is the signal that will attract storage.
• Mains use: grid integration of renewables, storage policy, contracts for difference, transmission planning, energy transition finance.

Revision Flowchart

Sources:

• Mint, Rituraj Baruah, “Is India’s solar power play facing its Icarus moment?”, 19 October 2026 (online), 20 October 2026 (print)
• PIB releases of 10 January 2026 and 3 February 2026; MNRE, physical progress as on 30 September 2026
• IRENA, Renewable Capacity Statistics 2026 (31 March 2026)
• EAC-PM Working Paper EAC-PM/WP/53/2026, “The Duck and The Camel: Tracing the Net Load on the Indian Power Grid”, Sanjeev Sanyal and Satvik Dev (July 2026)
• Ember, report on transmission gaps and curtailment in India (May 2026)
• Icra, Indian Renewable Energy Sector reports (March and June 2026)
• MNRE Office Memorandum on the CfD pilot (30 March 2026); PRS, Legislative Brief on the Draft Electricity (Amendment) Bill, 2025
• CEA, National Electricity Plan 2023; pv magazine India on the CEA draft amendment regulations (7 September 2026) and on BESS capacity (7 October 2026)

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