Great Indian power paradox: Record coal output but the grid still can't keep up

• Coal supply is at record highs, yet outages are spreading
  
  
• Solar is being switched off because coal cannot step aside
  
  

On paper, India's power sector should be celebrating. Coal India's South Eastern Coalfields Ltd (SECL) just reported an 8.2% jump in coal supply to the power sector in April, delivering 12.49 million tonnes (mnt). Production rose 9.25%. Stockpiles at pitheads are healthy. Railways are running extra rakes.

Yet, on the ground, the story is very different. Chandigarh is facing dry taps and power trips. Farmers in multiple states are alleging erratic supply and harassment by electricity companies. In Maharashtra, a major discom is reporting outages caused not by a lack of power, but by too much solar backfeed from residential rooftops. And a nationwide AC boom is threatening to trip the grid every evening.

Welcome to India's new power crisis. It is not a crisis of fuel. It is a crisis of timing, flexibility, and architecture.

Coal machine running at full steam

Let's start with what is working. SECL that operates the massive Korba coalfields in Chhattisgarh, has had a blistering start to FY2026-27.

• Coal supply to power sector: 12.49 mnt in April 2026, up 8.2% from 11.54 mnt in April 2025.
  
  
• Total coal production: 15.31 mnt, up 9.25%.
  
  
• Overburden removal: 33.10 million cubic metres, up 4.49%.
  
  
• Total offtake: 15.85 mnt, up 4.03%.
  
  

According to SECL's CMD, the company remains committed to sustaining this momentum and ensuring reliable coal availability to meet the country's power demand. Improved land availability in mega projects in the Korba region, plus focused monitoring of critical operations, has driven this performance.

This is not an isolated story. Across Coal India's other subsidiaries, production has been ramped up. The Ministry of Coal's directive to prioritise power sector supply has been followed diligently. The logistical chain -- first-mile connectivity, railway rakes, and port handling -- has largely held up.

So, if coal is flowing, why are lights flickering?

Heatwave and summer demand spike

April and May in India are always punishing. But 2026 has been particularly brutal. Early heatwaves have gripped central and northern India, with temperatures in parts of Madhya Pradesh, Vidarbha, and the National Capital Region touching 45-47C weeks earlier than usual.

The result is a predictable but massive surge in electricity demand:

• Air conditioner sales have exploded. India's AC market is growing at over 15% annually, with penetration still low but rising fast. Every degree of temperature rise above 35C adds roughly 2-3 GW of load nationally.
  
  
• Daytime power demand is being partially met by solar, which has crossed 150 GW of installed capacity. But solar collapses after 5:30 PM.
  
  
• Evening peak demand -- typically between 7 PM and 10 PM -- is hitting record levels, driven by ACs, lights, fans, and now, the early growth of EV charging and data centre loads.
  
  

The grid is managing, but barely. And the stress is showing up in strange places.

Strange new outages - too much solar, not enough flexibility

Here is where the paradox deepens. In Maharashtra, a major discom is reporting outages that are caused by high power demand from solar users.

How does that work?

Rooftop solar installations, especially net-metered ones, feed excess power back into the distribution grid during sunny afternoons. But many local distribution transformers and feeders were not designed for two-way power flow. Voltage fluctuations, reverse current, and protection relay trips have become common. In some areas, the influx of solar during the day is overloading local grid infrastructure designed for one-way flow from substation to consumer.

Meanwhile, in Chandigarh, residents are facing "power supply trips" and "taps go dry" -- because water pumps depend on electricity, and erratic supply means no water. The city's grid, like many urban networks, is struggling with the sharp ramp rates between solar noon and evening peak.

Farmers across multiple states are alleging erratic power supply and harassment by discoms. The typical pattern: daytime power for agricultural pumps is being curtailed or made erratic because discoms are prioritising urban AC load and struggling to manage the solar-induced voltage swings.

This is not a coal shortage. This is a grid flexibility shortage.

Real culprit - inflexible coal and the duck curve

The technical heart of the problem is well understood by power systems engineers, but rarely discussed in public.

India's coal fleet -- the vast majority of thermal plants -- cannot ramp down below 55-60% of rated capacity without risk of flame instability, thermal stress, and equipment damage. So even on a sunny afternoon when solar is generating 100+ GW, coal plants are legally and technically required to keep running at minimum load.

The result? Curtailment. As one industry analysis noted recently, around 2.3 terawatt-hours of solar power went unused in 2025 -- enough to power 400,000 homes for a year. That solar was literally switched off because coal could not step aside.

This is the infamous duck curve. Solar produces a bell-shaped curve peaking at noon. Demand rises slowly in the morning, dips slightly at midday (because solar meets some load), then rises sharply in the evening as the sun sets. Coal plants, unable to ramp down fast in the morning or ramp up fast in the evening, are ill-suited to this shape.

The AC boom - why evenings are becoming a nightmare

The evening peak is where the crisis becomes acute. A typical Indian summer evening sees:

• Solar output falling from ~80-100 GW at 4 PM to near-zero by 6:30 PM.
  
  
• AC load surfacing almost instantly as people return home and switch on cooling.
  
  
• Coal plants trying to ramp up from 55% to 90%+ load - a process that takes hours, not minutes.
  
  
• Gas-based peaking plants (where they exist) struggling with fuel availability and high costs.
  
  

The result is a demand-supply gap in the narrow window of 6 PM to 9 PM. This gap is currently filled by:

• Overloading coal plants beyond their design ramp rates, risking breakdowns.
  
  
• Load shedding in rural and semi-urban feeders (which is what farmers are experiencing).
  
  
• Voltage drops and trips in distribution networks (Chandigarh, the Maharashtra discom's jurisdiction).
  
  

As one power technology expert recently put it, "A high-renewable power system must be able to respond in less than five minutes." Coal cannot do that. Gas-based reciprocating engines can, but India has very few of them. Batteries can, but installed storage capacity remains tiny relative to need.

Solution pipeline - pumped storage moves forward

Not all news is grim. A significant development has occurred in the pumped storage space: a 1.35 GW order for the Upper Sileru project has been awarded to a major power technology firm. Pumped storage - essentially a water battery - pumps water uphill when solar is abundant (midday) and releases it through turbines when demand peaks (evening).

This is precisely the kind of long-duration, fast-response flexibility that India needs. Unlike coal, pumped storage can go from zero to full output in minutes. Unlike batteries (currently limited to 2-4 hours), pumped storage can provide 6-12 hours of storage.

The 1.35 GW Upper Sileru project is a drop in the ocean. India has a potential of over 100 GW of pumped storage, but less than 5 GW is operational. The new order suggests that the pipeline is finally moving - but it will take years to build.

Integrated assessment - what is really happening?

Let me put all the pieces together into a single coherent picture.

The integrated story is this: India has successfully secured coal supply. Production is up, offtake is up, and power plants are not starving. But the nature of demand has changed. Heatwaves and ACs have created sharp evening peaks. Solar has created a midday glut. The coal fleet cannot flex fast enough to bridge the gap between them. The result is not a blackout - but a slow bleed of curtailment, trips, and erratic supply that is hitting farmers, urban residents, and even water supply.

The SECL headline - "supply rises 8.2%" - is a success story of Indian mining and logistics. But it is also a warning. More coal, by itself, does not solve the evening peak. It does not fix two-way solar backfeed on distribution transformers. It does not give farmers reliable daytime power. It does not stop AC-driven ramp rates from tripping urban grids.

India's power sector has mastered the easy part: producing and moving coal. The hard part - building a flexible, renewable-integrated, consumer-reliable grid - is still ahead. And the heatwaves of 2026 are telling us, in no uncertain terms, that time is running out.