CEA Proposes Revised Thermal Ramping Framework to Reduce Plant Stress and DSM Exposure

The Central Electricity Authority (CEA) has recommended changes to the ramp rate compliance framework and scheduling methodology for coal based power plants, highlighting concerns over equipment stress, deviation settlement mechanism (DSM) charges and the challenges of flexible operation amid rising renewable energy integration.

The recommendations follow three meetings held in New Delhi in March, May and June 2026 involving CEA, Grid Controller of India, NTPC, BHEL, DVC, RRVUNL and Adani Power. The discussions focused on the technical limitations of thermal units in responding to ramping instructions and the impact of current scheduling practices on plant operations.

According to the CEA report, thermal generators may need to ramp at significantly higher instantaneous rates to achieve the required average ramp rate over a 15 minute scheduling block. NTPC said that achieving an average ramp rate of 1 percent per minute could require the unit to ramp at around 2.5 to 3 percent per minute during the active ramping phase, which typically lasts five to seven minutes.

The report noted that the present assessment methodology, based on changes in average generation between consecutive 15 minute blocks, does not fully capture the actual ramping behaviour of thermal units. Boiler response and stabilisation periods can result in little change in generation even after the ramping process has begun.

This can create a gap between scheduled and actual generation during ramping, potentially exposing generators to DSM charges even when units are operating within their technical ramping capabilities. The report also observed that generators may increase the quantum of load change to compensate for such deviations, resulting in ramp rates exceeding recommended limits and placing additional stress on thermal equipment.

CEA noted that frequent consecutive ramping, particularly when a ramp up is immediately followed by a ramp down, can further increase mechanical and thermal stress. BHEL highlighted that grid operators currently issue step load changes, whereas thermal units respond through a gradual ramping process.

The report proposed introducing a dedicated “ramping block” during which the target load would be achieved by the end of the block, followed by a stable load or stabilisation block before another ramp is initiated. Where load changes extend across several blocks, a single ramp command or multiple ramp commands separated by stable load blocks could be adopted.

The CEA also recommended avoiding consecutive ramp up and ramp down operations on the same units or plants. Instead, ramping schedules could be rotated among a pool of units or plants to distribute equipment stress. It suggested that the merit order dispatch framework may also need to be reviewed where necessary to support this approach.

For renewable integration, the report envisages a set of thermal plants ramping down to their minimum technical load during the morning as solar generation rises, remaining at minimum load during solar hours and ramping up in the evening as solar generation declines. The report said sufficient stabilisation time should be provided before a change in ramp direction.

The CEA further recommended reducing reliance on thermal power plants for fine grid balancing by using other flexible resources, including hydro power, gas based generation, pumped storage and battery energy storage systems.

The report noted that CEA regulations prescribe a minimum ramp rate capability of 3 percent per minute for coal based thermal generating units operating between 70 percent and 100 percent of maximum continuous rating, and 2 percent per minute between 55 percent and 70 percent. For operation between 40 percent and 55 percent, the report recommends keeping the ramp rate within 1 percent per minute.

The CEA has also proposed adopting an average scheduled ramp rate of 1 percent per minute between 55 percent and 70 percent load, with a maximum machine ramp rate of 2 percent per minute. For the 70 percent to 100 percent range, an average scheduled ramp rate of 1.5 percent per minute has been recommended, while an average ramp rate of 0.5 percent per minute has been suggested between 40 percent and 55 percent load.

The report also recommends installing battery storage at suitable locations for fine grid balancing and carrying out necessary amendments to the regulatory framework to implement the proposed measures.