India heatwave: 256 GW peak power demand tests grid

Early heat arrives before the monsoon

India is heading into what could be a long, punishing summer ahead of the monsoon rains expected in June, and the heat has already begun testing the country’s electricity system. The India Meteorological Department (IMD) had forecast in March that the country would see a higher than normal number of heat days, and it has continued to issue warnings. The IMD is set to publish its May outlook on Friday, covering what is typically the hottest period of the year. April’s warmer-than-usual conditions have pushed people and businesses to run cooling appliances for longer hours, keeping demand elevated through the evening and night. That round-the-clock load is where stress tends to build, because solar power falls away after sunset.

Record demand in April, with May still ahead

India’s peak power demand hit a historic 256.1 gigawatts (GW) at 3:38 pm on April 25, surpassing the previous day’s record of 252.07 GW and overtaking the earlier all-time high of 250 GW set in May 2024. Another report pegged the record at 256.11 GW on April 26, underscoring that the system was operating close to its limits over multiple days. The timing is notable because peak demand is often associated with June or July, but this spike arrived weeks earlier. The IMD warned of continuing heatwave conditions across northwest and central India, while temperatures across many parts of the country ranged between 40°C and 46°C. Delhi recorded 42.8°C on April 26, about 5.1°C above normal, marking the highest reading of the year there.

Heat extremes are showing up across cities

The pressure is visible on the ground. Data from digital air-quality monitoring platform AQI earlier this week showed that every one of the 50 hottest cities in the world was in India. AQI said India occupied the entire list from rank 1 to rank 50. With humidity adding to discomfort, nights have offered only mild relief in many places, extending the use of air conditioners, fans, and coolers well beyond the afternoon peak.

West Asia supply disruptions add to the squeeze

The heat-driven demand shock is hitting at a time when India is also managing energy supply constraints linked to conflict in West Asia. The disruption has tightened the availability of key fuels, including crude, liquefied natural gas (LNG), and liquefied petroleum gas (LPG), which is widely used for cooking. LNG constraints matter for the power system because gas-based plants can ramp quickly and are often used as a bridge when renewable output drops. When imports are hampered, that flexibility is reduced, putting more weight on coal and other sources during evening peaks.

The grid’s “double-peak” problem

India’s rapid addition of renewable capacity over the past decade has improved the ability to meet daytime demand, and coal generation has also revived to support supply. But the heatwave has highlighted a structural challenge: a “double-peak” pattern, where daytime demand is partly cushioned by strong solar output, while evening peaks still rely heavily on coal and gas. Solar accounts for about 30% of total generation capacity, but it contributes nothing at night, when residential consumption often rises due to cooling needs. Limited utility-scale battery storage means surplus daytime solar cannot yet be stored and deployed at scale after sunset.

Coal and gas were pushed hard to meet the peak

On the day the record was set, coal-fired power output rose to around 187 GW, and about 9.6 GW of gas-based capacity was also brought online. NTPC Ltd. procured gas through the Indian Gas Exchange and operated plants in line with Grid-India’s directions. Solar supported the daytime peak materially: solar energy contributed nearly 57 GW at the peak, about 22% of total supply, and earlier in the day solar output surged to nearly 81 GW, roughly one-third of generation at that moment. This combination helped meet the headline peak without a national shortage, a grid stress event, or major transmission bottlenecks, according to the report.

Outages and maintenance complicated the supply picture

Even with enough installed capacity on paper, availability became a key issue in the heat. Government data showed almost 21 GW of coal and nuclear capacity under maintenance shutdowns as of Tuesday, mostly due to forced outages. Since temperatures rose sharply in April, India reported night-time shortfalls as high as 5.4 GW, described as the equivalent of serving 2.7 million rural homes. Another account of the shortfall highlighted a spike in forced and partial outages in thermal plants: planned outages were expected around 3 GW, but forced and partial outages rose to nearly 26 GW. A senior official cited forced outages of around 18 GW in coal plants, plus 3-4 GW of partial outages, totaling around 21 GW of unavailable capacity.

Why blackouts still showed up locally

Several areas reported more frequent blackouts even as the national grid managed the record peak. Deficits in generation are one reason, but high heat can also degrade the performance of power equipment, with overloading compounding the stress created by ambient temperatures. Residents have complained on social media and, in some cases, in local reports and street-level protests. Punjab, among the early provinces to face scheduled blackouts, saw the main opposition party Shiromani Akali Dal organise a protest. A power distributor executive in Noida, Sarnath Ganguly of Noida Power Co. Ltd., pointed to discipline on both sides: consumers being more diligent and distribution companies identifying overloaded transformers and improving capacity before the summer.

Key numbers from the heatwave-driven surge

Supply mix at the record peak

Why this matters for investors and policy

The April surge shows how extreme heat is reshaping India’s load curve and operational requirements, particularly after sunset. The system can post record daytime peaks with help from solar, but evening reliability still leans on thermal plants, and forced outages during high heat can quickly translate into shortfalls. The fuel backdrop adds another layer: constraints in LNG supply reduce flexibility just as the grid needs fast-ramping capacity. For power-sector planning, the episode underlines the importance of improving thermal reliability, distribution readiness, and storage and flexibility solutions that can shift daytime renewable output into the evening window.

What to watch as May approaches

The IMD’s May outlook, due Friday, will be a key marker for how severe the next phase of heat could be. The IMD’s seasonal outlook for April to June 2026 projects above-normal heatwave days across much of east, central, and northwest India, as well as the southeast peninsula, suggesting May could be more punishing than April. The government has said it deferred maintenance of nearly 10,000 MW of coal-fired capacity to July and remains confident of meeting a projected seasonal peak of around 270 GW. Whether that confidence holds will depend on equipment availability, the ability to manage evening peaks, and the extent of fuel constraints during sustained heat.

Conclusion

India’s early heatwave has pushed electricity demand to around 256 GW in late April and exposed the grid’s most vulnerable hours at night, when solar drops and thermal reliability becomes decisive. With higher-than-normal heat days expected in the April to June window and May still ahead, the next test will be sustaining supply through evening peaks while managing outages and local distribution bottlenecks.