A committee constituted by the Central Electricity Authority (CEA) has called for operating thermal power plants at a minimum technical load (MTL) of 40% and adopting two-shift operations to support grid stability amid increasing renewable energy integration.

In a draft report on the wear and tear, operations and maintenance, and plant lifespan implications of coal-fired power plants due to flexible operations, the committee concluded that operating thermal plants at 55% MTL had not resulted in significant damage attributable solely to flexible operation, countering concerns raised by NTPC over wear and tear due to low-load running.

According to the report, GRID-India told the committee that India’s power system was increasingly experiencing a pronounced “duck curve,” with surplus renewable energy during mid-day hours and steep evening ramp requirements of about 60 GW. National ramping needs range between 250–300 MW per minute, reaching up to 500 MW per minute on certain days, while diurnal demand variation is about 75 GW.

GRID-India recalled that on May 25, 2025, despite backing down the national thermal fleet to about 58% and curtailing nearly 10 GW of solar power, system frequency rose to 50.48 Hz, which is above the Indian Electricity Grid Code (IEGC) band. This called for deeper thermal fleet flexibility.

The grid recorded persistent high frequency above the IEGC band of 49.90-50.05 Hz for over 20% of the time on 39 days during the third and fourth quarters of the financial year 2024-25.

The committee noted that achieving India’s target of 500 GW renewable energy capacity and 50% non-fossil energy by 2030 will require flexible thermal operations down to 40% MTL to restrict renewable energy curtailment, two-shift operations, battery storage, and pumped storage solutions.

NTPC told the committee that it had been witnessing increased boiler tube leakages, flame failures, and turbine-generator issues, which it attributed to thermal fatigue from low-load operations and frequent ramping.

However, the committee’s analysis of operational data from two units did not establish a conclusive link between 55% MTL operation and significant damage.

Retrofits and Advanced Control Systems

CEA had already notified regulations for phased implementation of 40% MTL by 2030, following pilot studies demonstrating feasibility. The committee emphasized that safe and sustainable flexible operation requires appropriate retrofits, advanced control systems, and operator training.

It stressed the need to conduct pilot studies for two-shift operation, particularly on smaller and older 210 MW units, to scientifically assess wear and tear and establish compensation mechanisms.

In October 2025, the Central Electricity Regulatory Commission (CERC) also recommended that states enable two-shift operation of intrastate thermal generating stations in the wake of growing renewable energy integration.

Although CERC directed a pilot project in March 2025, NTPC sought an exemption, citing operational and reliability concerns.

The committee warned that the absence of pilot data has delayed the formulation of an evidence-based regulatory framework for two-shift operations.