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Delhi's electricity demand has surged into the monsoon months of 2025 due to rising humidity and heat index, despite fewer heatwaves.
The increased demand, peaking at night, highlights the growing discomfort from humid heat.
The analysis by CSE emphasises the need for improved thermal comfort measures and energy-efficient solutions to manage the escalating electricity burden.
Despite a summer with fewer heatwaves, Delhi's electricity demand has gone up, a new analysis showed. The high demand also sustained longer in 2025, spilling deeper into the monsoon months, due to high heat index in the range of 46-50°C.
Heat index is the "feels like" temperature now seen on weather dashboards, along with the actual temperature. It factors in the relative humidity of a place along with temperature.
As it becomes hotter and more humid, people switch on their cooling devices, such as air conditioners or coolers, to escape heat stress. This pushes up the electricity demand. Monitoring electricity demand is crucial because it has become a sensitive marker of heat stress.
During Delhi's monsoon months that are becoming gradually wetter than earlier, the heat index shoots up, dragging along the cooling demand.
The humid heat became more unbearable this August compared to the last, as indicated by the higher electricity consumption, according to the policy brief by Delhi-based think tank Centre for Science and Environment (CSE). “In August 2025, the average peak demand was about 2 per cent higher compared to August 2024, despite wetter conditions this year. Nearly half of the days in August 2025 (16 out of 31) recorded higher peak demand than the same days in 2024.“
The month's electricity demand also peaked earlier in 2025 compared to 2024, the authors of the policy brief added. “August is increasingly behaving like a peak summer month, with rising demand loads that stretch the grid beyond its traditional summer stress period.“
The researchers also observed a strong correlation between daily electricity demand peak and heat index. This means, power demand rises in lockstep with temperature and humidity. “67 per cent of the variation in Delhi’s daily peak electricity demand can be explained by cooling demand responding to how hot and humid it feels outside,“ they wrote in the policy brief eleased September 8, 2025.
Another significant trend in 2025 was that the cooling demand peak occured at night (11.09 pm) compared to the afternoon surges seen till last year. This can be explained by the 42 per cent loss in cooling at night in 2025 compared to the average of 2001-2010. This means, due to higher nighttime temperatures, the mercury dip from day to night is smaller, causing higher thermal discomfort at night and increases impact on health.
“During the monsoon months in 2025, the daytime and nighttime land surface temperatures have risen by about 2.1°C and 3.0°C, respectively, compared to 2024. At the same time, the day-night cooling difference has narrowed down -- thus reducing the cooling window. This is adding to the heat distress,” said Sharanjeet Kaur, deputy programme manager, urban lab, CSE.
She added that April 2025 registered higher electricity consumption than April 2024, reflecting a much warmer start to the summer this year.
March 2025 recorded a moderate growth of 4.6 per cent in overall energy use compared to March 2024, yet peak power dipped slightly, the analysis showed. In August 2025, peak demand rose to 7,050 megawatts (recorded on 8 August), about 2 per cent higher than the previous year.
In 2024, the highest electricity demand was of 8,656 MW. Despite wetter conditions in 2025, the peak in June still exceeded 8,400 MW, indicating that the demand for cooling in early summer is now firmly established. In August 2024, the peak demand reached 6,890 MW.
According to CSE, Delhi's electricity demand reached 8,442 MW on June 12, 2025, at 11:09 PM, making it the second highest peak ever recorded in the city. This figure was just 2.5 percent below the all-time high of 8,656 MW, which was achieved last summer on June 19, 2024.
In the decade since 2015, the peak electricity demand in Delhi has surged from 5,846 MW to 8,442 MW — a 44 per cent rise.
“There is an urgent need for Delhi and other regions to rethink the approach to managing intensifying summer heat, heat index and the growing electricity burden, with both short and long term measures,” said Anumita Roychowdhury, executive director-research and advocacy, CSE.
The organisation outlined the following solutions in the policy brief:
The heat action plans need stringent compliance framework for implementation of the thermal comfort measures in buildings: This requires binding and mandatory implementation of the regulations related to energy efficiency and thermal comfort requirements in buildings including Energy Conservation Building Code, and Eco-Niwas Samhita, Standards and Labelling of appliances, district cooling systems among others, and adoption of passive cooling solutions including passive architectural design, reflective surfaces, shading, natural ventilation, better insulation and adoption of energy efficient cooling technologies in buildings. Adopt cooling as a service model.
Implement thermal comfort measures in affordable housing and create cooling shelters of low-income groups and build awareness on management of heat stress for all income categories.
Expand urban green and water bodies and increase permeability by reducing concrete surfaces to reduce the urban heat island effect.
The heat action plans need to acknowledge the link between the heat index and peak electricity load and integrate climate and heat-related indicators into power system planning: This requires forecasting models based on weather data with real-time demand to help power operators to anticipate peak surges more accurately and prepare for it, improve grid stability, and ensure reliable supply of power when it is most needed.
Ensure uninterrupted power supply especially for essential services. The regions will require better load balancing and easin of grid strain during high-demand hours.