India's grid could not absorb 6,825 gigawatt-hours of renewable power in the first half of 2026, 4.9% of renewable generation and 1.8 times the whole of 2025, per Aurora Energy Research. September's curtailment fell to 378.52 million units, 1.28% of renewable output, which JMK Research called seasonal relief rather than a fix.
Tamil Nadu now requires new solar and wind-solar hybrid projects above 1 megawatt to install batteries worth at least 10% of their solar capacity. The Solar Energy Corporation of India has tendered 16,000 megawatt-hours of standalone storage in Rajasthan and Gujarat, with bids due November 19. The Ministry of New and Renewable Energy says battery capacity has grown from roughly 0.7 gigawatt-hours to nearly 10 in ten to eleven months, and expects the gap between renewable plants and their wires to narrow over 18 months.
Why it matters
If India can't add grid flexibility fast, the world's third-largest carbon emitter hits a buildout ceiling, and global decarbonization timelines slip with it.
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Key Indicators
118.6 GW
Curtailed in September 2026
Renewable capacity affected by curtailment in September, including 96.9 GW of solar and 21.7 GW of wind, per JMK Research. The month's curtailed energy was 378.52 million units, 1.28% of renewable generation.
6,825 GWh
Renewables curtailed, H1 2026
Renewable generation the grid could not absorb from January to June 2026, 4.9% of renewable output and 1.8 times the whole of 2025, per Aurora Energy Research. Solar accounted for 4,729 GWh, concentrated in Rajasthan and Gujarat.
8,133 GWh
Solar held back Apr-Jun
Solar generation the government says was not absorbed in April-June 2026: 2,417 GWh in April, 3,235 GWh in May, 2,481 GWh in June, per the renewable minister's written statement.
33%
New capacity curtailed
Share of India's recently commissioned renewable capacity (54.8 GW) reliant on temporary grid-access routes, per ICRA (July 2026). Curtailment on these routes runs 50-60% during peak solar hours.
~10 GWh
Battery storage online
Battery capacity has grown from about 0.7 GWh to nearly 10 GWh in ten to eleven months, MNRE joint secretary J.V.N. Subramanyam said. The CEA projects 236 GWh is needed by 2032.
25 events
Latest: October 30th, 2026 · 1 week ago
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October 2026
Tamil Nadu mandates batteries on new solar; SECI tenders 16,000 MWh of storage
LatestPolicy
Mercom India's Q3 2026 policy roundup reported Tamil Nadu's Battery Energy Storage Systems Policy, 2026, which requires new solar and wind-solar hybrid projects of 1 MW and above to install storage equal to at least 10% of solar capacity. It also flagged a SECI tender for 2,500 MW/10,000 MWh of standalone storage in Rajasthan and 1,500 MW/6,000 MWh in Gujarat, with bids due November 19.
Aurora Energy Research: 6,825 GWh curtailed in first half of 2026
Analysis
The grid curtailed 6,825 gigawatt-hours of renewable power from January to June 2026, 4.9% of renewable generation and 1.8 times the whole of 2025, Aurora Energy Research found. Solar accounted for 4,729 gigawatt-hours, with losses concentrated in Rajasthan and Gujarat.
MNRE: transmission gap should narrow within 18 months as batteries reach 10 GWh
Government
J.V.N. Subramanyam, joint secretary at the Ministry of New and Renewable Energy, said transmission projects take about 36 months to build against 12 to 18 months for a solar or wind plant, and that recently commissioned lines should close the gap over 18 months. He said battery storage has grown from about 0.7 gigawatt-hours to nearly 10 gigawatt-hours in ten to eleven months.
KEC International wins Rs 2,872 crore of POWERGRID orders for 765 kV lines
Infrastructure
KEC International took turnkey orders worth Rs 2,872 crore from Power Grid Corporation to design, supply and install 765-kilovolt transmission lines supporting evacuation of 8.5 gigawatts of renewables from Gujarat. The contracts lifted KEC's 2026 order intake above Rs 13,500 crore.
CREA: 1,835 MU curtailed in July-August; storage meets up to 5.5 GW of night peak
Analysis
The Centre for Research on Energy and Clean Air put July-August curtailment at about 1,835 million units, 1,462 from solar and 373 from wind. Storage supplied up to 5.5 GW during nighttime peak demand, up from 4.1 GW the previous quarter, and roughly 290 GWh of storage tenders had been issued by August.
September 2026
CEA proposes mandatory two-hour batteries on new solar and wind projects
Regulatory
The Central Electricity Authority proposed requiring two-hour battery storage equal to at least 10% of installed capacity for all new solar and onshore wind projects commissioned after July 1, 2027. India had 8.6 GWh of BESS operating at the time, with 42.53 GWh under construction and 38.42 GWh awarded.
September curtailment affected 118.6 GW of renewable capacity
Data
JMK Research reported that curtailment touched 118.6 gigawatts of renewable capacity in September, including 96.9 gigawatts of solar and 21.7 gigawatts of wind, and cost 378.52 million units of generation, 1.28% of the month's renewable output. Solar was 314 million units of that.
August 2026
POWERGRID selected for 6,500 MW Gujarat renewable evacuation project
Infrastructure
POWERGRID was declared successful bidder for a high-voltage network moving power from the Jam Khambhaliya Renewable Energy Zone Phase II (5,500 MW) and Jamnagar Phase I (1,000 MW), under a build-own-operate-transfer model at an annual tariff of about Rs 823 crore.
July 2026
Government reports 8,133 GWh of solar held back in April-June
Data
Renewable minister Yesso Naik told parliament that 8,133 gigawatt-hours of solar output was curtailed in the June quarter, with monthly figures of 2,417, 3,235 and 2,481 GWh. The ministry attributed the cuts to transmission commissioning lagging renewable projects and to grid security requirements.
Power Grid Corporation commissions 765 kV Bhadla II-Sikar II transmission line, adding 1,100 MW of Rajasthan solar evacuation
Infrastructure
POWERGRID commissioned the 765 kV double-circuit Bhadla II-Sikar II transmission line through its tariff-based competitive bidding subsidiary PBSTL, adding 1,100 megawatts of evacuation capacity from the Bhadla, Ramgarh, and Fatehgarh solar complexes. Rajasthan is one of the two states where ICRA documented peak curtailment of 50-60% during solar hours.
India adds 30.6 GW of renewables in H1 2026; solar capacity reaches 162 GW
Data
India added 30.6 gigawatts of renewable capacity in the first half of 2026, up 25% on the same period last year, per Power Minister Pralhad Joshi. Solar led with 26.34 GW added, a 43% year-on-year jump. Total installed renewable capacity, including large hydro, reached 288 gigawatts — 52% of all installed generation capacity.
MNRE formally opposes CERC's uniform grid-discipline penalties for wind and solar
Regulatory
India's Ministry of New and Renewable Energy formally asked CERC to maintain separate deviation settlement rules for wind and solar rather than aligning them with thermal generator standards. MNRE warned that equal deviation charges across all generator types would raise project risk and weaken developer bankability, potentially pushing tariffs higher.
Equirus Capital: grid-discipline rules due April 2027 could cut solar revenues 11%, wind up to 48%
Analysis
Equirus Capital's July 2026 Infrastructure Tracker estimated that stricter grid-discipline penalties, due to take effect in April 2027, could cut solar revenues by 11% and wind revenues by up to 48%. Solar and wind generators struggle to match scheduled grid commitments because weather varies, and the proposed rules would penalize shortfalls more heavily.
CERC orders release of 15.7 GW of stranded interstate transmission capacity
Regulatory
CERC issued a one-time order to release up to 15.7 gigawatts of interstate transmission capacity held by projects that received letters of award between 2019 and 2025 but never signed power purchase agreements. Freed slots go first to projects in the same substation cluster, then to open auction at Rs 3 lakh per MW.
ICRA: one-third of new renewable capacity on temporary grid routes, 12% of transmission projects on time
Analysis
ICRA found about 33% of India's 54.8 GW of recently commissioned renewable capacity is evacuated via temporary general network access routes, with curtailment hitting 50-60% during peak solar hours in Rajasthan and Gujarat. Just 12% of tariff-based competitive bidding transmission projects were commissioned on their scheduled date, with median delays exceeding 10 months.
June 2026
Ember: India needs 10 GWh of storage now; curtailed 2.1 TWh in FY2025-26
Analysis
Ember reported that India curtailed 2.1 terawatt-hours of renewable electricity across FY2025-26 — 1.3% of total renewable generation — costing developers roughly Rs 629 crore. It estimated that 10 GWh of battery storage charged during peak solar hours would have prevented all of it, and that coal plants breached the 55% floor in over half of midday dispatch intervals by April 2026.
GEON commissions 2.88 GWh battery project at Khavda in five months
Infrastructure
GEON, the future technologies division of Kabra Extrusiontechnik, commissioned a 2.88 GWh battery system at Khavda, Gujarat, completed in five months and adding to a growing cluster of grid-scale storage at India's largest renewable hub.
May 2026
ReNew discloses curtailment and profitability hit
Corporate disclosure
Bloomberg reports that ReNew Energy Global is being forced to curb solar output and is taking earnings hits because India's grid cannot absorb mid-day solar peaks.
January 2026
Ministry of Power releases Draft National Electricity Policy 2026 for public consultation
Policy
The Ministry of Power published a draft NEP to replace the 2005 policy. It classifies storage as foundational grid infrastructure, targets 411 GWh of grid-connected storage by 2031-32, and mandates coal plants reduce minimum technical load from 55% to 40% by 2030.
2026
Adani Green commissions 3.37 GWh BESS at Khavda
Infrastructure
Adani Green Energy reached 3.37 GWh of operational battery storage at its Khavda renewable hub in Gujarat, built in roughly ten months; Ember dates the commissioning to May 2026.
December 2025
Ember estimates 2.3 TWh of solar lost in H2 2025
Analysis
Energy think tank Ember reports India curtailed roughly 2.3 terawatt-hours of solar generation in the second half of 2025, largely for grid security reasons.
Argus Media documents rising solar curtailment volumes, attributing them to insufficient transmission, storage, and inflexible coal dispatch.
June 2024
First curtailment warnings emerge from regional grids
Operational
Rajasthan and Karnataka grid operators begin reporting periodic solar curtailment during low-demand hours, raising early warnings to developers.
May 2023
CEA publishes National Electricity Plan flagging storage gap
Planning
The Central Electricity Authority projects India needs roughly 47 gigawatts of battery storage by 2030 to integrate planned renewable capacity.
August 2022
India sets 500 GW non-fossil capacity target for 2030
Policy
Prime Minister Narendra Modi confirms India's pledge to reach 500 gigawatts of non-fossil power capacity by 2030, accelerating solar and wind tenders.
Scenarios
1
India fast-tracks storage mandates, curtailment eases by 2027
Likely
Discussed by: Bloomberg NEF, Ember, and Indian Ministry of Power consultations
New Delhi accelerates battery storage tenders and an expanded Energy Storage Obligation on distribution companies, pairing solar additions with co-located batteries. Inter-state transmission corridors already under construction come online, giving Grid-India room to absorb mid-day surplus rather than curtail it. Developers sign storage-bundled power purchase agreements at scale, and curtailment rates plateau by late 2027.
2
Coal minimum load floor lowered, more solar reaches the grid
Possible
Discussed by: Argus Media, CEA technical committees, thermal generators
The Central Electricity Authority revises the 55% minimum thermal load downward—possibly to 40%—after technical studies confirm modern coal units can ramp deeper without damage. Coal generators receive compensation for cycling losses. The reform unlocks immediate solar headroom but faces resistance from state-owned thermal operators worried about plant wear and stranded capacity.
3
Solar buildout slows as developers retreat from grid-constrained states
Possible
Discussed by: Industry analysts at CRISIL, ICRA, and BloombergNEF
Persistent curtailment pushes developers to pause new project bids in Rajasthan, Gujarat, and Karnataka, where grid congestion is worst. ReNew and peers redirect capital toward green hydrogen, exports, and markets with firmer evacuation guarantees. India misses its annual capacity addition targets, and the 500 GW by 2030 goal slips by two to three years.
4
Demand-shifting reforms unlock daytime solar absorption
Uncertain
Discussed by: Power Ministry, distribution company associations
India accelerates time-of-day tariffs and large-load shifting—agricultural pumping, industrial cooling, and electrolyzer hydrogen production—into mid-day hours. Combined with rooftop solar growth and electric vehicle charging incentives, daytime demand rises to meet solar peaks, easing curtailment without major new transmission or storage spend.
5
Transmission delays keep curtailment elevated through FY2027-28 despite new storage
Possible
Resolves by Q1 2028
Discussed by: ICRA analysts and Ember (June–July 2026 reports)
Only 12% of India's tariff-based competitive bidding transmission projects have been commissioned on schedule, with a median delay of over 10 months. If the next pipeline — 107 GW of projects already granted grid connectivity — faces the same execution drag, new battery storage at Khavda and planned tender wins won't offset the gap. Curtailment could hold above 2% of renewable generation through FY2027-28, slowing investor returns and deterring new bids in congested states.
6
Two-hour batteries become mandatory on every new solar and wind farm
Likely
Resolves by Jul 1, 2027
Discussed by: Central Electricity Authority, Ministry of New and Renewable Energy
The CEA's September 3 proposal would require two-hour battery systems equal to at least 10% of installed capacity on all new solar and onshore wind projects commissioned after July 1, 2027. Storage economics would shift from optional add-on to entry cost, raising upfront capex per project while cutting the midday surplus that drives curtailment. Adoption depends on whether the proposal survives industry comment and how the connectivity rules for grid charging are written.
7
State storage mandates spread beyond Tamil Nadu
Possible
Resolves by Q2 2027
Discussed by: Tamil Nadu's BESS Policy 2026, reported in Mercom India's Q3 2026 policy roundup
Tamil Nadu requires new solar and wind-solar hybrid projects of 1 MW and above to install batteries equal to at least 10% of solar capacity. If Gujarat, Rajasthan or Maharashtra write similar rules, storage becomes a standard cost of new renewable projects instead of an optional add-on, trimming the midday surplus that drives curtailment in those states.
Historical Context
3 moments from history that rhyme with this story — and how they unfolded.
1 of 3
2014-2020
California duck curve (2014-2020)
As California's solar fleet crossed roughly 10 gigawatts, the California Independent System Operator's mid-day net load curve sagged into the now-famous 'duck' shape. Solar generation at noon began outstripping demand, and grid operators curtailed renewable output—peaking at over 1.5 terawatt-hours curtailed in 2020.
Then
California began paying neighbors to take surplus power, sometimes at negative prices, and curtailed an increasing share of solar generation each year through 2020.
Now
The state mandated procurement of grid-scale batteries—reaching over 10 gigawatts by 2024—and curtailment rates stabilized as storage absorbed the mid-day peak and discharged it into the evening ramp.
Why this matters now
California faced the same mid-day surplus problem India is now hitting, and the fix that worked—massive battery storage paired with market reforms—is exactly what India's CEA and Grid-India have begun to plan but not yet procured at scale.
2 of 3
2015-2017
China wind curtailment crisis (2015-2017)
Wind curtailment in China's Inner Mongolia, Gansu, and Xinjiang provinces hit 30-43% in 2016, with developers losing tens of billions of yuan to forced output cuts. Local coal plants kept running for heat and employment reasons, while transmission to coastal demand centers lagged the wind buildout by years.
Then
Beijing imposed regional caps on new wind approvals in the worst-affected provinces and ordered grid operators to prioritize renewable dispatch.
Now
China built ultra-high-voltage transmission lines linking interior wind farms to eastern load centers and reformed dispatch rules. National wind curtailment fell below 4% by 2020.
Why this matters now
China's experience shows that curtailment from inflexible coal plus transmission shortfalls is solvable—but only through aggressive transmission buildout and dispatch reform, both of which India has been slower to execute.
Germany's rapid wind buildout in the windy north outpaced transmission to industrial demand in the south. Operators paid to curtail wind farms and used 'redispatch' payments to fire up southern fossil plants, with redispatch costs climbing past €1.4 billion in 2017.
Then
Consumers absorbed the redispatch costs through grid fees, and several planned wind projects in the north were paused pending transmission approval.
Now
Germany approved major north-south transmission corridors, but legal and local opposition delayed completion by nearly a decade. The episode reshaped how European countries plan transmission alongside generation.
Why this matters now
Germany is the cautionary tale: building generation faster than the wires that carry it produces curtailment, higher consumer costs, and political backlash. India is at the early stage of the same gap, with most renewable capacity in the western and southern states but demand spread nationwide.
