Key Details
The Central Electricity Authority’s Report on Ramp Rate Compliance Framework and Scheduling Methodology for Coal-Based Thermal Power Plants, dated 21 August 2026, examines whether 15-minute scheduling and existing commercial rules adequately reflect how coal units physically change output.
Operational diagnosis: Coal plants cannot move instantaneously from one scheduled output level to another. Boiler response, active ramping and stabilisation occur sequentially, creating an unavoidable gap between scheduled and actual generation during a ramp.
Machine stress: Generators reported using active ramp rates of around 2.5–3% per minute to deliver an average change of 1% per minute across a 15-minute block. Consecutive ramps and immediate reversals can increase thermal and mechanical stress.
Minimum-load operation: The report supports operating coal units at a minimum technical load of 55%, progressively falling to 40%, to accommodate higher solar generation while limiting equipment damage.
Scheduling proposal: It recommends a distinct ramping block, followed by a stable-load block before another ramp or reversal. Ramp instructions could also be rotated across a wider pool of plants.
Revised ramp rates: Suggested 15-minute average rates are 0.5% per minute between 40% and 55% load, 1% between 55% and 70%, and 1.5% between 70% and 100%.
Alternative flexibility: Hydropower, gas plants, pumped storage and battery energy storage systems (BESS) should increasingly provide fine grid balancing instead of requiring coal units to make continuous small adjustments.
Regulatory action: The report says corresponding changes will be needed in the applicable scheduling, ramp-rate and Deviation Settlement Mechanism provisions. These remain recommendations, not notified amendments.
What Is a Ramp Rate?
A power plant’s ramp rate measures how quickly it can increase or decrease electricity generation, usually expressed as a percentage of its maximum capacity per minute. Higher renewable penetration increases the need for ramping because conventional plants must adjust when solar or wind output changes.
The Deviation Settlement Mechanism financially settles differences between a generator’s scheduled and actual electricity supply. It supports grid discipline, but its design must distinguish avoidable deviations from differences inherent in technically normal ramping.
Renewable Integration Is Changing the Role of Coal Plants
As solar generation rises during the day, coal plants are increasingly expected to reduce output in the morning, remain at lower load during solar hours and ramp up as solar generation declines in the evening.
The CEA report accepts that this flexibility is essential to integrating renewable energy. Its concern is with using coal units for repeated fine balancing throughout the day, rather than with low-load operation itself. It identifies frequent, high-magnitude ramping and rapid reversals as the more serious source of equipment wear.
The proposed operating pattern is therefore simpler: one managed ramp-down, several hours at minimum load and one managed evening ramp-up, with adequate time for equipment to stabilise.
Fifteen-Minute Scheduling Does Not Match the Physics of a Thermal Ramp
Current schedules are expressed as output levels for 15-minute blocks. A coal plant, however, takes time to respond after receiving a command and reaches the new target progressively.
To meet the average output required for a block, generators may compensate for the initial boiler-response delay by ramping much faster during the active phase. According to NTPC’s submission, producing an average ramp of 1% per minute can require an instantaneous ramp of approximately 2.5–3% per minute for five to seven minutes.
This creates a mismatch between three things:
the scheduled block-level generation;
the plant’s actual physical response; and
the ramp rate against which its performance is assessed.
The report argues that forcing plants to reproduce a step-like schedule can encourage operation beyond recommended conditions, potentially increasing maintenance requirements and shortening component life.
Commercial Rules Can Penalise Technically Normal Ramping
Differences between scheduled and actual energy can attract charges under the Deviation Settlement Mechanism (DSM). Generators told the CEA that such deviations arise during ramping even when a unit is operating within its technical capability.
The report proposes recognising a dedicated ramping block in which the plant reaches the target at the end of the block and scheduled energy reflects the gradual—not instantaneous—change in output. It also recommends revisiting the ramp-rate benchmarks used for financial incentives and penalties.
Grid-India offered a counterpoint: generators can begin changing output during the preceding block, and DSM regulations already recognise deviations within prescribed limits. It also reported that the introduction of Security Constrained Economic Despatch (SCED) reduced the number of scheduled-change blocks by 29% and their cumulative megawatt quantum by 42% during April–December 2019.
The regulatory question is therefore not whether ramping should be measured, but whether the existing combination of scheduling, performance incentives and deviation charges accurately rewards technically safe flexibility.
Merit-Order Dispatch May Need to Account for Equipment Stress
Traditional merit-order dispatch prioritises plants largely according to variable generation cost. The report proposes considering the frequency and direction of ramping, potentially rotating instructions across a pool of plants instead of repeatedly calling on the same unit.
Such an approach could raise short-term power procurement costs if a slightly costlier plant is dispatched to protect another unit from repeated cycling. The possible offset is lower operation and maintenance expenditure, fewer equipment failures and longer plant life.
This introduces a broader cost question: the cheapest dispatch in one scheduling block may not be the lowest-cost option after accounting for maintenance, plant availability and long-term system reliability.
Storage and Flexible Generation Should Handle Faster Balancing
Coal units can provide large changes in output over the morning and evening transition periods, but they are less suited to continuous small adjustments and quick reversals.
The report therefore recommends assigning more fine-balancing responsibility to batteries, pumped storage, hydropower and gas-based generation. This would differentiate between:
slower, sustained flexibility, which coal plants can provide; and
fast, frequent balancing, for which storage and more responsive generating sources are better suited.
Sufficient storage at strategically selected grid locations is thus presented not merely as renewable-energy infrastructure, but as a way to reduce the operating stress imposed on the existing thermal fleet.
Policy Relevance
The report exposes a coordination problem at the centre of India’s power transition. Renewable-capacity targets, thermal-plant engineering, electricity scheduling and commercial settlement rules cannot be designed independently.
The immediate task is regulatory: CEA’s technical ramp-rate standards, CERC’s tariff and DSM provisions, and the scheduling procedures followed by load despatch centres need to measure flexibility on a consistent basis. Otherwise, a plant may comply with its physical limits yet face a commercial penalty—or chase a commercial target by placing excessive stress on its equipment.
Over the longer term, the recommendations strengthen the case for evaluating storage, pumped hydro and flexible generation as system assets. Their value includes not only shifting renewable power across time, but also reducing cycling, maintenance costs and reliability risks across the coal fleet.
Any revision must still protect grid discipline. More accommodating ramping rules should not become a general exemption from accurate scheduling. The aim is to distinguish physically unavoidable ramp deviations from inefficient plant performance.
Follow the Full CEA Report Here: Report On Ramp Rate compliance framework And Scheduling Methodology for the coal-based power plant