India's solar buildout hits grid flexibility limits

Overview

Updated Jul 28

India added 30.6 gigawatts of renewable capacity in the first half of 2026, bringing total installed renewables to 288 gigawatts, but curtailment is worsening in step. Coal plants hit the 55% minimum thermal floor in over half of midday dispatch intervals by April 2026. One-third of the 54.8 gigawatts of recently commissioned capacity flows only through temporary grid routes, with curtailment running 50-60% during peak solar hours in Rajasthan and Gujarat.

Power Grid Corporation commissioned the 765 kV Bhadla II-Sikar II transmission line in Rajasthan on July 20, adding 1,100 megawatts of evacuation capacity from the state's worst curtailment zones. CERC released 15.7 gigawatts of stranded interstate slots in early July, but its proposed April 2027 grid-discipline penalties could cut solar revenues 11% and wind revenues up to 48%, per Equirus Capital. India's Ministry of New and Renewable Energy is formally opposing those penalties, warning that equal deviation charges for wind, solar, and thermal generators would raise project risk and push tariffs higher.

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

55%

Coal minimum load

Mandated thermal floor — breached in over half of midday dispatch intervals by April 2026 as solar generation overwhelms grid capacity.

2.1 TWh

Solar lost in FY2025-26

Ember's confirmed curtailment figure for the full April 2025–March 2026 fiscal year, worth roughly Rs 629 crore in lost developer revenue.

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.

Target market rank

India's plan to surpass the US as the world's second-largest solar market in 2026.

15+ GW

ReNew portfolio

Operational and contracted renewable capacity across solar, wind, and hybrid projects.

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People Involved

Sumant Sinha

Founder, Chairman and CEO, ReNew Energy Global

Publicly disclosing curtailment-driven hits to profitability

Organizations Involved

ReNew Energy Global

Renewable energy producer (Nasdaq-listed)

Curtailing solar output, reporting profitability impact

India's largest pure-play renewable independent power producer, selling solar, wind, and hybrid power mostly to state distribution companies under long-term contracts.

Grid-India (National Load Dispatch Centre)

State-owned grid operator

Managing coal dispatch at or below the 55% minimum floor in over half of midday intervals as solar generation continues to climb

Operates the National Load Dispatch Centre, balancing supply and demand across India's five regional grids in real time.

Central Electricity Authority

Statutory technical body

Draft NEP 2026 issued for public consultation; mandates coal minimum technical load reduction to 40% by 2030 and targets 411 GWh of grid-connected storage by 2031-32

India's statutory technical authority that sets grid codes, plans transmission, and approves large generation projects.

Adani Green Energy

Renewable energy producer (NSE/BSE-listed)

Commissioning large-scale BESS at Khavda as direct response to curtailment constraints

Part of the Adani Group conglomerate; operates India's largest single renewable energy hub at Khavda, Gujarat, targeting 30 GW of capacity there by 2029.

Central Electricity Regulatory Commission (CERC)

Regulatory Body

July 11 order released 15.7 GW of stranded ISTS capacity; proposed April 2027 grid-discipline penalties now facing formal opposition from MNRE

India's electricity tariff regulator and grid-access rule-setter for interstate markets, separate from the CEA's technical planning function.

Power Grid Corporation of India Limited (PGCIL)

State-owned transmission utility

Commissioned Bhadla II-Sikar II 765 kV line July 20; won RECPDCL bid for 4.5 GW ISTS project July 27

India's national interstate transmission company, responsible for building and operating the high-voltage lines that carry power from generation hubs to demand centers.

Timeline

August 2022 July 2026

16 events Latest: July 20th, 2026 · 1 month ago Showing 8 of 16

Tap a bar to jump to that date

July 2026
Power Grid Corporation commissions 765 kV Bhadla II-Sikar II transmission line, adding 1,100 MW of Rajasthan solar evacuation
Latest 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.
July 20th, 2026
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.
July 17th, 2026
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.
July 17th, 2026
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.
July 15th, 2026
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.
July 11th, 2026
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.
July 8th, 2026
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.
June 17th, 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.
June 16th, 2026
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.
May 6th, 2026
March 2026
Adani Green commissions cumulative 3.37 GWh BESS at Khavda — world's largest single-location deployment outside China
Infrastructure

Adani Green Energy reached 3.37 GWh of operational battery storage at its Khavda renewable hub in Gujarat, the world's largest single-location deployment outside China, built in roughly ten months from groundbreaking.
March 1st, 2026
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.
January 30th, 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.
December 31st, 2025
July 2025
Argus reports curtailment exposing India's grid gaps
Reporting

Argus Media documents rising solar curtailment volumes, attributing them to insufficient transmission, storage, and inflexible coal dispatch.
July 1st, 2025
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.
June 1st, 2024
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.
May 1st, 2023
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.
August 1st, 2022

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Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

2011-2018

Germany's Energiewende grid bottleneck (2011-2018)

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.

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.

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.