New Delhi: India’s power grid has developed a new weak spot. As temperatures climb past 45°C and electricity demand surges, solar power is helping the grid meet demand during the day. But night is becoming a different story.
After sunset, several parts of the country are witnessing power outages as the grid struggles to meet evening demand once solar supply fades, according to three people aware of the matter and grid data reviewed by Mint.
According to Sanjeev Aggarwal, founder and chairman, Hexa Climate, a renewable power generator, the challenge is now faced from 6-10 pm, when the sun is gone and demand is still high. “That gap is now the defining problem of India’s grid,” he said.
The supply crunch has been aggravated by the fact that around 40 gigawatts (GW)—15% of India’s generation capacity of 239 GW—is currently under forced outage largely due to technical faults.
The stress pushed India’s energy shortage to 15.87 million units (MUs) on Tuesday, according to data from Grid Controller of India—enough electricity to power around three million households for a day, according to the people cited above.
The shortfall amounted to 0.2% of overall demand, far higher than the 0.05% permissible limit set by the Central Electricity Authority.
Most of the shortage occurred in the northern and western regions—especially in Maharashtra, Haryana and Punjab—driven by a combination of inadequate storage capacity, outages at thermal power plants, and discoms depending heavily on expensive short-term electricity markets instead of long-term supply contracts.
“These days, energy shortage is ranging above 13-14 MUs, which has led to load shedding in several parts. Usually, it’s much less than 10 MUs,” said a former Grid Controller of India executive, requesting anonymity.
“What is mostly talked about is the peak demand in the solar hours, but the main issue is faced in the peak of non-solar hours,” said Alok Kumar, director general of the All India Discoms Association (AIDA).
Power shortages—and load-shedding—have been ongoing this month in the midst of the heatwave. On Monday (25 May), the total energy shortage was 11.24 MUs. And on 21 May, when demand touched a record high of 270.82GW with an evening peak of 246GW, the shortage was 15.02 MUs. Again, the shortages were led by Maharashtra, Haryana and Punjab, in that order.
The demand in Punjab is likely to increase further next month, according to Basant Garg, chairman and managing director, Punjab State Power Corp. Ltd (PSPCL).
“Currently, our peak power demand ranges between 12,500MW and 13,000MW, mainly during the evening hours when households switch on air conditioners and agricultural consumers also draw electricity,” Garg said. “However, the trend may change in the upcoming paddy season (starting 1 June) as we expect demand to peak at 17,500MW during the daytime, compared to 16,600MW last year.”
Garg added that PSPCL has made extensive arrangements to ensure that farmers are not affected.
Queries emailed to the Union power ministry and power departments of Maharashtra, Uttar Pradesh and Haryana remained unanswered till press time.
High demand, low supply
Kumar of AIDA, who also served as the power secretary to the Union government, pointed out that several discoms do not sign adequate long-term power purchase agreements (PPA) and instead depend on spot purchases from exchanges because of fund shortages and concerns over delay in projects.
“Further, buy bids on exchanges are higher than sell bids in the evenings. And on a pro-rata basis, many discoms get less than the required power, causing shortages,” added Kumar.
To be sure, data from the India Energy Exchange (IEX) showed that bids to buy power (or demand) on its real-time market (RTM) platform were almost double the bids to sell power (or supply) during 21-28 May, despite RTM prices hitting the ₹10 per unit price cap on a daily basis due to the high demand from the heatwave situation.
A report by Ember, a global think tank focused on energy transition, released on 19 May, said: “Despite prices hitting market caps, supply availability has remained constrained, with more than 10-20GW of demand going unmet in several instances during March and April of 2026,” the Ember report said.
Where are the batteries?
Given that wind and solar cannot generate round the clock, batteries can help salvage the situation in evening peak hours. However, compared to plans of installing 47 gigawatts (GW) of battery storage capacity orders by FY32—requiring $38 billion of investment—the current capacity is just 795 megawatt hours (MWh), according to government estimates.
Noting that battery costs are down almost 70-80% in the past three to four years, Aggarwal of Hexa Climate said a four-hour battery charged on cheap midday solar and discharged into the evening peak is now commercially viable in a way it was not even two years ago.
An official with a Haryana discom, requesting anonymity, said battery energy storage systems are being deployed, but discoms remain reluctant because the systems may be used heavily only during a few peak-demand days each year, while the costs have to be borne year-round.
To be sure, weather patterns play a key role in operations of the power system. As witnessed earlier this week, sudden rains and calming temperatures in a few days along with ease in industrial demand led to prices on exchanges hitting zero, a paradox given that the prices have also hit the price cap of ₹10 during the same month.
Meanwhile, the India Meteorological Department (IMD) said severe heatwave conditions have begun easing across parts of northwest India, including Delhi and adjoining regions, aided by changing weather systems and likely thunderstorm activity.
However, isolated parts of Rajasthan, east Madhya Pradesh and Vidarbha are expected to continue witnessing severe heatwave conditions till 29 May, while thunderstorms and squally winds across several regions between 29 and 31 May could bring temporary relief but also disrupt normal life.