New Delhi: India's solar expansion has reduced midday fossil generation by 10 GW, from 135 GW at 1 pm in H1 2023 to 125 GW in H1 2026, according to a new analysis by energy think tank Ember. The think tank said this is equivalent to the output of around 15 modern coal-fired power units, but noted that coal generation after sunset continues to rise as demand grows, pointing to battery storage as the means to extend daytime solar into the evening.
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Ember said solar generated a record 10 percent of global electricity in the first half of 2026, making it the fastest-growing source of electricity worldwide. Its contribution still falls to near zero after sunset, the think tank said, leaving the evening hours dominated by fossil fuels.
On the average day in H1 2026, Ember said, fossil generation fell to around 125 GW at 1 pm, about 10 GW below the level recorded at the same time in H1 2023. After sunset, however, fossil generation between 5 pm and 7 am averaged 168 GW, 22 GW higher than three years earlier. Coal plants ramp down through the middle of the day before ramping back up sharply to meet evening demand, according to the analysis.
"India has shown how quickly solar can reduce coal generation during daylight hours," said Kostantsa Rangelova, Global Electricity Analyst at Ember. "The next step is extending those benefits beyond sunset. Battery storage allows cheap daytime solar to meet evening demand, reducing pressure on coal-fired generation while making better use of renewable electricity that would otherwise go unused."
Ember estimated that batteries expected to be installed in 2026 could theoretically shift 34 percent of new daily solar generation into the evening, based on solar growth in H1 2026 — almost double the share in 2025 and up from 4 percent in 2021. The think tank said California now meets more than a quarter of its evening electricity demand with solar and batteries, while Bulgaria has expanded battery deployment to move a significant share of solar generation beyond daylight hours.
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For India, Ember said, battery storage will become increasingly important as solar continues to grow. Alongside reducing dependence on evening coal generation, batteries can help limit renewable curtailment, improve utilisation of existing solar capacity and strengthen grid flexibility, according to the analysis. The think tank said realising these benefits will depend not only on continued battery deployment, but also on electricity market reforms that enable storage to participate fully across energy and ancillary service markets.
