#plf

Installed capacity is still climbing, but October 2025 shows India’s generation engine running softer—exactly the kind of “transition volatility” grid operators are now learning to manage in real time.

Using the Central Electricity Authority’s (CEA) executive summaries for September and October 2025, all-India generation eases from 155.85 BU in September to 141.33 BU in October, even as the country’s installed capacity moves past 505 GW by end-October. The headline tension is simple: India is adding megawatts quickly (especially non-fossil), but the system is not necessarily using that expanded fleet as hard during shoulder months.

The shoulder-month utilisation gap is widening

September still looks relatively firm in year-on-year terms, but October resets the narrative. Generation is not only down sharply from September, it is also lower than October 2024—a meaningful correction right after monsoon. Yet capacity rises from 500,889 MW (end-September) to 505,023 MW (end-October).

That’s the utilisation gap in one line: more capacity on paper, less energy delivered in the month. This gap matters because it changes how planners should think about “adequacy”—not just installed MW, but seasonal performance, hourly reliability, and dispatchability.

Thermal PLFs take the real shock

CEA PLF tables show the October hit is broad-based. Thermal PLFs (excluding gas) were already softer in September, but October is where the fall becomes impossible to ignore—almost a nine-percentage-point year-on-year drop, with state and IPP fleets among the hardest hit.

This is not just a plant-specific story. It looks more like system-wide merit-order optimisation under softer demand and changing renewable/hydro conditions—exactly the environment where thermal units shift from baseload to balancing role, and utilisation becomes more lumpy.

Hydro and renewables dip despite capacity additions

Hydro also underperforms in the October snapshot. Large hydro generation falls from 22.32 BU (September) to 16.44 BU (October), reflecting post-monsoon inflow tightening and seasonal limits on hydro’s ability to stabilise the system across months.

On the renewables side, September appears strong, but October sees RES generation slip to 21.49 BU, even as renewable capacity rises by over 3.3 GW in a single month. Cumulatively, renewables still show strong year-on-year growth—but October reminds us that short-term output is ruled by weather profiles, curtailment decisions, and grid integration constraints, not just capacity growth.

Why this matters: MOD, costs, and market design

For dispatch and grid operators, the September–October sequence highlights how merit order dispatch (MOD) has become more complex: softer demand and variable renewables can back down thermal quickly, altering logistics, maintenance cycles, and unit economics.

For regulators, the signals point to bigger design questions:

How should capacity charges and availability norms evolve when thermal increasingly behaves like flexible/reserve capacity?

Are current compensation pathways sufficient for essential reliability services (ancillary services, reserves, balancing)?

How should planning frameworks reflect a system where annual/cumulative generation can rise, even while individual months show deep utilisation troughs?