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Even as India enjoys a surge in low-cost renewables, its coal-fired generation is widely expected to keep growing too — with all the planet-heating carbon emissions that entails.

Could the rise of large-scale batteries change the picture?

Near the edge of a sun-baked salt marsh in northern Gujarat, a vast new battery array highlights a tantalising opportunity for India and the global climate: to slow, or even reverse, the country’s rising demand for coal-fired power.

This is where Adani Green Energy — part of a conglomerate controlled by Gautam Adani, Asia’s richest man — is developing a giant solar and wind park that already has more than nine gigawatts of installed capacity. By 2029, the company says, that will rise to 30GW — roughly two-thirds of Great Britain’s peak power demand — making this by far the biggest renewable facility in the world.

But while India’s renewable power investment is booming, generation from carbon-spewing coal power plants remains the backbone of the country’s electricity mix, and is projected to expand further in the years ahead as a source of steady “baseload” power for the growing economy.

Last week, an Adani Green Energy announcement underscored that India now has a different path available to it. The company said it had brought into operation a battery system at the Gujarat plant with a capacity of 3.37 gigawatt-hours — enough to power the state of Goa for a whole day, and bigger than any such installation outside China, it claimed.

It’s certainly far bigger than any such project yet seen in India, which had less than 1.1GWh of battery storage in the whole country at the end of last year, according to research group Mercom. Adani says this is just the start, with plans to raise the storage capacity at the Khavda solar plant to 10GWh by next year, and 50GWh by 2031.

The investment reflects a technology shift with important implications for the global energy transition. Over the past two years, dramatic declines in battery prices have meant that renewable power plants, paired with storage systems, can now provide round-the-clock power at a cost competitive with fossil-fuelled plants.

The Adani group has been in the headlines for far less positive reasons over the past couple of years. US authorities in 2024 launched cases against its founder, and group businesses including Adani Green Energy, over alleged bribery and fraud. Criminal fraud charges against Gautam Adani were dropped last month, soon after other authorities agreed to settle two other cases. This came after Adani’s legal team highlighted the tycoon’s willingness to invest $10bn in the US, the FT reported.

But if Adani’s giant battery installation in Gujarat can help galvanise a broader wave of energy storage investment, there would be benefits for India and the wider world.

Old king coal

Coal’s grip on the Indian power system has already shown some signs of slipping. Last year, coal-fired generation fell by 3 per cent — the first such fall for more than 50 years, apart from a pandemic-driven slump in 2020.

But this was a blip, not a turning point, reckon analysts at the International Energy Agency, noting unusually slow growth in Indian power demand last year, driven partly by mild temperatures that reduced air conditioning needs.

Coal-fired generation is set to return to growth in the coming years, with India’s overall coal demand expected to rise at an annual rate of 3 per cent, the IEA forecasts. While low-cost renewables now account for the bulk of new capacity, power authorities continue to see a need for coal plants to provide stable baseload power that complements intermittent wind and solar.

“Power grids are run by engineers,” said Rohit Chandra, an energy policy expert at the Indian Institute of Technology Delhi. “They care about reliability, resilience, and minimising power outages.”

Yet a growing weight of research suggests that renewable systems, when coupled with battery storage, can now provide power far more reliably and economically than was previously possible.

New economics

The cost of utility-scale batteries has declined by more than half since 2022 and 27 per cent last year alone, according to BloombergNEF.

Last month, the International Renewable Energy Agency published research finding that renewable-plus-storage plants can now provide power at competitive cost for more than 95 per cent of the hours in the year across much of the world.

An India-focused study published in March, by the India Energy and Climate Center at the University of California, Berkeley, found that co-located solar plus storage facilities can now provide baseload power at a lower cost than coal plants.

Serious expansion in battery storage is now essential to the sustainable growth of low-carbon power in India, reckons Sumant Sinha, chief executive of ReNew Power, the country’s second-largest renewables developer after Adani. “You can’t just keep adding more renewables without batteries,” Sinha told me recently. “That is very critical.”

Yesterday the state-owned power company NTPC launched a tender for the development of a battery installation at a solar plant in Rajasthan, with a total storage capacity of 7.8GWh — more than double the current figure for Adani’s plant in Gujarat.

The government has promised to support greater investment in battery storage systems, to support its goal of achieving 500GW of non-fossil generating capacity by 2030. With over 50GW installed last year, it’s currently on pace to meet that target.

But the battery storage advances mean India now has the opportunity to raise its green energy ambitions and save money in the process, argue researchers at the Council on Energy, Environment and Water, a prominent New Delhi-based think-tank.

If India can reach clean power capacity of 600GW rather than 500GW by 2030, reckons CEEW, it would enjoy extra savings of $1.5bn in power system costs — on top of the benefits for the global climate and local air pollution.

“We still see headlines that [Indian] coal consumption is going up,” CEEW chief executive Arunabha Ghosh told me. “But the real story is how the solar plus storage technology is improving. I think the peak of coal, at least in power generation, will be sooner than many anticipate.”

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