India needs around 10 GWh of battery energy storage capacity immediately to prevent renewable energy curtailment caused by the operational limits of coal-fired power plants, according to a new analysis by energy think tank Ember, which warned that the country’s rapidly expanding solar fleet is beginning to outpace the grid’s flexibility.
The report estimates that 2.1 terawatt-hours (TWh) of renewable electricity was curtailed in FY26 solely to keep coal plants operating above their minimum technical load (MTL), equivalent to 1.3% of India's total renewable generation and about ₹629 crore worth of foregone electricity.
The findings come as India adds solar capacity at a record pace. The country installed around 24 GW of solar capacity between October 2025 and April 2026, taking total installed solar capacity to nearly 154 GW. During this period, solar and wind generation increasingly pushed coal plants towards their technical operating floor of around 55% of rated capacity, beyond which they cannot safely reduce output.
“Solar and wind curtailment is becoming a visible part of India’s real-time grid balancing, and the volumes are already noticeable and rising. Without sufficient flexibility, including storage, this could become a constraint on the next phase of renewable energy growth,” said Neshwin Rodrigues, Senior Energy Analyst at Ember.
Midday Squeeze
The report highlights the growing mismatch between India’s renewable expansion and the flexibility available in the conventional fleet. On March 6, 2026, solar and wind accounted for 41% of the country’s generation mix at midday, forcing coal generation to decline by nearly 49 GW within six hours before ramping up by 51 GW in just three hours during the evening demand surge.
By April 2026, coal generation had breached its minimum technical load in more than half of all midday dispatch intervals, leaving little room for further downward regulation. As a result, renewable curtailment accounted for 37% of total down-regulation requirements in April 2026, compared with almost zero a year earlier.
“This is curtailment required purely to keep coal plants at their MTL. Before the system even considers reserve requirements or grid constraints, renewable generation is being cut simply to make space for coal to remain operable. The constraint is structural,” Rodrigues said.
According to Ember, emergency TRAS-down curtailment of solar and wind generation has crossed 3,600 GWh by early June 2026, up from near-zero levels in mid-2025. Since March this year alone, more than 1,400 GWh of additional curtailment has been recorded, while renewable curtailment exceeded 120 GWh on both May 1 and May 3.
The report noted that coal continues to provide almost all of India’s balancing reserves. In March 2026, coal supplied 1,351 MU out of 1,364 MU of regulation-up reserves and 1,984 MU out of 2,395 MU of regulation-down reserves, underscoring the heavy reliance on thermal plants for grid balancing.
Ember estimates that around 9-10 GWh of battery storage charging during midday solar hours would have been sufficient to absorb surplus renewable generation, keep coal above its technical minimum and eliminate most curtailment witnessed during FY26.
Overcoming Regulatory Bottlenecks
The report cited the 3.37 GWh Khavda battery project in Gujarat, commissioned within 10 months, as evidence that deployment timelines are not the challenge. Instead, it said grid connectivity regulations restricting battery charging from the grid are emerging as the key bottleneck.
“The current framework has the default the wrong way around. It restricts the very operation that would help the system most. Correcting it would allow storage to charge when it reduces curtailment, lowers system stress, and improves flexibility,” Rodrigues said.
Source: Financial Express
No comments:
Post a Comment