India's Scorching Nights Strain Power Grid, Threaten Health

India's dangerously torrid summer days have long been a climate warning. Now the country is increasingly dealing with sweltering nights too, as global warming and poor urban planning put millions at risk.

For eight of the past 10 years, average minimum temperatures during March to May - a proxy for nighttime heat over the pre-monsoon season - have been higher than the long-term average, according to data from the India Meteorological Department. Only 2020 and 2023 bucked the trend.

Earlier this month, the IMD warned this summer would again see above-normal minimum temperatures across India. That means heat will linger even when cooler weather should instead be allowing humans and power infrastructure to recover from the day's strain, putting both at risk.

"Sustained high temperatures through the night are becoming a bigger cause of heat exhaustion than the day-time heat," said Rohit Magotra, a director at New Delhi-based think-tank Integrated Research and Action for Development, or IRADe, who advises the Indian government on heat mitigation. "Especially for people without access to adequate water and consistent, affordable cooling."

Part of the problem is a changing climate - India is one of the most vulnerable nations when it comes to the effects of rising temperatures. 

But hotter nights are also the consequence of so-called urban heat islands, when concrete in densely packed neighborhoods absorbs daytime solar radiation and slowly releases the trapped heat at nights, pushing the indoor temperatures above the outside readings. In the poorest areas of India's cities, inhabitants often work outdoors by day - and now struggle to recuperate in the evening.

"Climate change is driving baseline temperatures higher, but the way we build our cities is what traps that heat," said Vishwas Chitale, team lead for climate resilience at the New Delhi-based Council on Energy, Environment and Water. "More than half of extreme heat in India cities is driven by rapid concretization and expanding road networks."

Higher heat means increased power consumption, and India has seen demand driven to repeated records, not only during the day but at night, resulting in occasional shortfalls. Add in overloaded - and sometimes poorly maintained - distribution networks, and several parts of the country have seen blackouts, from Delhi in the north to Chennai in the south.

Daytime demand has been met, in part thanks to the fast expansion of solar power. But evening supplies are far more stressed, exacerbated this year by the Iran war that has hampered liquefied natural gas supplies and reduced the utilization of gas power plants.

India has bought fuel on the spot market to meet peak demand - but generation has still been lower, resulting in a daily supply shortfall of as much as 5 gigawatts this season, enough to power some 3 million low-income households.

Among the worst-hit states is Uttar Pradesh, the country's most populous province and home to some of its hottest cities. A survey released by community social media platform LocalCircles on May 21 said 93% of homes in the state have been facing daily power outages, some for as long as eight hours.

Images of people protesting blackouts in various parts of the state have circulated on social media, while political leaders across parties, including the ruling Bharatiya Janata Party, have written letters to the state's energy minister A.K. Sharma, describing hardships caused by the erratic power supply.

Banda, a town in a semi-arid area of the state, has repeatedly topped the list of hottest cities in the world, its maximum daytime temperature reaching close to 48C on several occasions. The nights there have been equally harsh with minimum mercury readings consistently hovering near 35C level -  well past thresholds considered perilous to human health.  

"During the day-time, it seems like a weather-induced curfew in Banda," said Naseer Ahmad Siddiqui, a local activist and journalist. "After dark, public places are packed with residents seeking relief from their suffocating indoor quarters."

Sarnath Ganguly, senior vice president at Noida Power Co. Ltd., which distributes power in Noida on the outskirts of Delhi, argues responsibility falls to customers as well as utilities, with many exceeding their contracted power load with air-conditioners and other appliances.

If customers declare their actual usage and distribution utilities make arrangements on time, blackouts can be minimized, he said.

But for those with limited means of cooling, the most common solution to stiflingly hot nights is to stay out as long as possible - a fix that still leaves the elderly, pregnant women, young children and outdoor workers particularly vulnerable, according to CEEW's Chitale.

"Outdoor heat gets all the policy attention," he said. "But indoor heat is where the infrastructure deficit becomes lethal, especially for those without access to active cooling."

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)