The Duck and The Camel: Why India Must Store Its Sunshine

On 21 May 2026, India’s power grid set an all-time record. At 3:45 PM, the country was drawing 270.8 GW of electricity, more than at any moment in its history. But the record was only half the story. At 8:00 AM that morning, demand was 224.1 GW. In less than eight hours, the grid took on an extra 46.7 GW, more than the entire British grid supplied at its peak in 2025.

Now look at what electricity cost that day. On the Indian Energy Exchange’s Day-Ahead Market (IEX-DAM), a unit scheduled for 1:00 PM delivery cleared at Rs 1.56. The same unit scheduled for 6:30 PM cleared at Rs 10, the market ceiling. Interestingly, at 3:45 PM, the moment of record demand, the price was nowhere near its peak, because the sun was still up. It got there only at 6:30 PM, after sunset, and remained pinned to the ceiling thereafter.

The sun is the story that matters for the Indian grid today. India has built solar at remarkable speed: 157 GW of capacity by May 2026, or 29% of all installed capacity, up from 2% a decade ago. By law, solar is used first whenever it is available. So the task for the rest of the generators, the majority of which are coal powered thermal plants, is to meet the leftover demand (or ‘net load’) once solar has made its contribution. In summer, India’s net load traces what operators worldwide call the ‘duck curve’: a deep belly or trough at midday, when solar floods in, and a steep climb each evening, when it withdraws. Winter produces a double-humped Bactrian camel: one hump in the morning as the country wakes up cold and switches on heaters and lights, a midday dip, and a second hump after dark.

A new EAC-PM working paper (‘The Duck and The Camel: Tracing the Net Load on the Indian Power Grid’, July 2026) tracks these shapes over several years using grid data recorded every fifteen minutes, and the trend is hard to miss. Compare an average May day in 2023 with one in 2026. Night-time net-load grew by roughly 40 GW. Yet the midday net-load barely moved, staying pinned near 150 GW, because the growing solar fleet absorbed almost all the extra daytime demand. The evening climb or ramp-up (1 PM to 8 PM), meanwhile, doubled from about 36 GW to 74 GW, and the morning ramp-down (6 AM to 11 AM) nearly tripled, from 18 GW to 53 GW. The winter camel has steepened the same way, with both ramps now around 64 GW. Every year, the conventional generators are being asked to swing harder and faster to ‘follow the load’. This is both costly and inefficient.

The energy market mirrors this growing volatility. The average midday price on the IEX-DAM in May fell from Rs 2.81 per unit in 2023 to Rs 1.11 in 2026, while the average evening peak rose from Rs 8.08 to Rs 9.71. The peak to trough price spread is widening every year. The grid is also throwing solar power away: on an average day in May 2026, about 24 GWh of solar generation was deliberately switched off because the system could not absorb it. That is more than a quarter of Delhi’s average daily electricity consumption, discarded hours before the same grid strained to meet the evening peak. And strain it did. Across April and May 2026, the grid fell short of demand at the non-solar hours’ peak on 36 of 61 days, but at the solar hours’ peak on only 6. The country has plenty of electricity at midday. The squeeze comes after sunset.

The obvious answer is to store the midday surplus and release it in the evening. The arithmetic, however, is sobering. Halving even a single May day’s evening climb would need about 130 GWh of storage discharge between 1 PM and 8 PM. India’s entire storage fleet, pumped hydro and batteries combined, discharged about 23.8 GWh per day, on average, in May 2026. Against CEA’s projection of 8.68 GW of batteries by 2026-27, only 0.27 GW stood installed in January 2026, and though rapid additions in recent months have lifted this to 2.7 GW, the shortfall remains large.

The benefits for the grid of having a large storage build-out are well documented. The California grid, from where the term ‘duck-curve’ originated, has a battery fleet large enough to absorb/charge up to 8 GW during the midday and discharge over 10 GW into the evening. The result: an evening ramp up in net-load of nearly 28 GW shrinks to about 10 GW after adjusting for battery discharge.

Indian policymakers are cognizant of the challenges and have already put a draft framework in place to reshape the sector. The draft Electricity (Amendment) Bill, 2025 writes energy storage into the law for the first time, hardens the non-fossil purchase obligations with explicit penalties, and empowers regulators to deepen power markets, especially by introducing contracts for difference. The draft Electricity (Rights of Consumers) Amendment Rules, 2026 add demand response and set firm deadlines for time-of-day tariffs, so that bills can finally reflect the fact that a 1 PM unit and a 6:30 PM unit are very different things. These are welcome steps. But they will also pull even more solar onto the grid, and every new gigawatt of solar deepens the midday glut and steepens the evening climb unless storage grows alongside it. India has solved the problem of generating enough electricity. The next problem is supplying it at the right time.

Sanjeev Sanyal is Member, Economic Advisory Council to the Prime Minister (EAC-PM) and Satvik Dev is Joint Director, EAC-PM. Views are personal.