CEA Panel Flags Thermal Plant Stress As India Pushes Flexible Operations For 500 GW Renewable Target

A committee led by the Central Electricity Authority (CEA) is studying how India’s thermal power plants can operate more flexibly as the country moves toward its target of 500 GW of renewable energy capacity by 2030. The study focuses on how coal-based plants can adjust their output to support the grid when solar and wind power fluctuate. This includes “flexible operation,” where plants reduce generation to as low as 40% of their installed capacity, and “two-shift operations,” where units are frequently started and stopped depending on renewable energy availability.

The issue has become important as India adds large amounts of renewable power to its grid. Solar generation peaks during the day, often leading to excess supply, while demand rises in the evening when solar output falls. To maintain grid stability, coal plants are expected to ramp down during high renewable generation and ramp up quickly when renewable output drops. However, this shift has raised operational concerns among thermal power operators.

State-run power major NTPC has expressed serious concerns about the technical impact of such flexible operations. According to the company, there has been a sharp increase in equipment failures across its plants in recent years. Between 2021 and 2025, NTPC reported 692 boiler tube leakages across its fleet. The company argued that frequent ramp-ups and ramp-downs increase stress on equipment, accelerate wear and tear, and shorten plant life. It also said that operating below 55% capacity is technically difficult due to poor coal quality, which affects stable combustion. As a result, NTPC has been hesitant to participate in pilot projects involving two-shift operations.

However, equipment manufacturers and technical experts have offered a different assessment. Bharat Heavy Electricals Limited (BHEL) and Intertek stated that while flexible operation can increase life consumption of components, most of the observed damage may not be directly caused by low-load running. They suggested that up to 70% of the damage is likely linked to the older age of many thermal units, inadequate maintenance practices, and sub-optimal operating conditions over the years. According to experts, thermal stress builds up mainly during poorly managed start-ups and shutdowns, rather than during steady low-load operation.

The committee also examined operational data from NTPC’s Farakka and Jhajjar power plants. The analysis showed that ramp rates remained within conservative limits, and there was no clear evidence directly connecting low-load operations to the reported failures. Experts emphasized that with proper technical upgrades, improved control systems, and better training of plant operators, the risks associated with flexible operation can be reduced.

Meanwhile, Grid-India highlighted the urgent need for flexibility in the system. It noted that more than 23 GW of renewable energy had to be curtailed during periods of high solar generation because thermal plants could not reduce output quickly enough. This curtailment represents a loss of clean energy and affects overall system efficiency.

The committee concluded that while the transition to a more flexible grid presents challenges, it is necessary for supporting India’s clean energy goals. It has directed NTPC and other utilities to identify older 210 MW units for pilot studies on two-shift operations. The aim is to develop scientific guidelines for compensation, maintenance practices, and operational standards. The findings suggest that instead of resisting change, the focus should be on modernizing existing coal plants to safely and efficiently support India’s renewable energy expansion.