Beyond Lithium: Why India Must Rethink Grid-Scale Energy Storage for Long-Term Energy Security

By Rishi Srivastava & Dr. Tejas Kusurkar, Cofounders Offgrid Energy Labs

For half a century, India has measured its energy insecurity in barrels of oil. More than 85 per cent of the crude that moves the economy is imported, and every government since Independence has treated that dependence as a strategic wound to be healed. So it is worth pausing on a quieter fact. The renewable grid now being built to close that wound is on course to open another one — in batteries, and this time in a single country.

The renewable transition is usually told as a story of generation: the solar parks rising across Rajasthan and Gujarat, the wind farms along the coasts, the headline target of 500 GW of non-fossil capacity by 2030. That story is real and largely on track. But generation is the easier half of the problem. The harder half is time. The sun sets; demand does not. Wind answers to weather, not to the evening cooking peak or the air-conditioning load of a heatwave. A grid that runs on renewables is a grid that must move energy across hours — and the only way to do that at scale is to store it.

India’s Renewable Energy Ambition Faces a Storage Challenge

The numbers make the scale unavoidable. The Central Electricity Authority projects that India will need roughly 74 GW and 411 GWh of storage by 2031–32, of which about 236 GWh must come from batteries rather than pumped hydro. Today the country has only a small fraction of that in place. This is not a supporting detail of the energy transition; it is one of its central engineering constraints — and, as it turns out, one of its central strategic ones.

For most people, “battery” means lithium-ion, and for good reason. Over two decades, lithium-ion did something genuinely remarkable: it packed more and more energy into less and less weight and volume, and in doing so made the smartphone, the laptop and the electric car possible. It is one of the defining technologies of the age, and it earned its dominance honestly. Where weight and space are the binding constraints — anything that moves — it remains close to unbeatable.

Why Grid Storage Needs a Different Battery Strategy

A battery bolted to a substation is solving a different problem. It does not have to be light; it has to be cheap over its lifetime, safe in a crowded environment, stable in Indian heat, and willing to charge and discharge every day for ten to fifteen years. Energy density — the quality that made lithium-ion famous — matters far less here than longevity, thermal safety, recyclability and the plain question of whether the materials can be sourced at all. The chemistry optimised for the car is not automatically the right chemistry for the grid. Treating the two as one question is the first mistake.

The Hidden Risk: Replacing Oil Dependence with Battery Dependence

The second is to ignore where lithium-ion comes from. Here the parallel with oil returns. By most estimates China refines roughly three-quarters of the world’s lithium and around 80 per cent of its cobalt, and produces close to 98 per cent of the lithium-iron-phosphate cathode material that dominates stationary storage. India refines effectively none of it. For all the announcements of gigafactories, India’s actual cell-manufacturing capacity stood at roughly one gigawatt-hour at the end of 2025 — against some 60 GWh of capacity merely to assemble imported cells into packs. The country’s lithium-ion import bill has risen roughly eightfold in six years, from about US$384 million in 2019 to more than US$3 billion in the last financial year.

This is oil dependence rebuilt in a new material — except that crude has many suppliers and a deep global market, while battery-grade lithium and cathode chemistry have, for now, essentially one. When that supplier began restricting graphite exports in 2023, the warning was not subtle. Energy storage has quietly become an instrument of industrial statecraft, and a grid built on imported cells is a grid whose reliability is decided elsewhere.

None of this argues for abandoning lithium-ion, which will remain essential for mobility and for short-duration grid tasks. It argues for widening the question. And once the question is widened — which chemistry best fits stationary, long-duration Indian storage — other answers come into view.

Zinc-Based Batteries Could Power India’s Storage Future

The most interesting are zinc-based aqueous batteries. Their advantage begins with a chemistry almost opposite to lithium-ion’s. Where lithium-ion carries its energy in a flammable organic solvent, these systems use a water-based electrolyte, which all but removes the risk of thermal runaway — a serious consideration for storage sited next to homes, factories and substations. Zinc is abundant, inexpensive, already woven into existing industrial supply chains, and easier to recover at end of life. Many zinc systems can also be discharged fully, without the degradation penalty that forces lithium-ion to hold back a reserve — a meaningful gain when every kilowatt-hour on the grid counts.

The honest case requires stating the trade-offs too. Zinc-based systems store less energy per kilogram than lithium-ion, and for years they were held back by dendrite formation and short cycle life. Those were real limitations. But there were limitations of engineering, not of physics, and recent advances in electrolyte design, electrode architecture and interface stabilisation have narrowed them considerably. For a stationary application that prizes safety, longevity and material security over weight, the balance increasingly tilts the other way.Recycling sharpens the point. The lithium-ion batteries being installed today will become tomorrow’s waste, and recovering their materials at scale is technically demanding and energy-intensive; India’s recycling base for advanced chemistries is barely formed. Zinc, by contrast, is recovered through industrial processes the country already runs. Designing storage with its own end of life in mind is not an environmental nicety — it is an industrial decision about whether value stays in India or leaves it.

And here India holds cards it rarely plays. It is among the world’s largest zinc producers, with mining and refining ecosystems already at scale, and it has deep scientific talent across electrochemistry, materials science and process engineering, much of it trained in Indian institutions. What it has lacked is the bridge between the laboratory and the factory floor — the patient capital, the manufacturing incentives and the policy attention that turn a promising chemistry into an industry. That bridge cannot be imported.

The procurement decisions India makes over the next few years will lock in its grid for decades. If it simply buys the cheapest available cells, it will buy a familiar kind of dependence along with them. If instead it aligns research, industrial policy and manufacturing around chemistries suited to its own conditions and built from its own materials, it has the rarer chance to leapfrog — to own a category of storage rather than rent it.

For fifty years, India’s energy security was a question of what it had to import. The promise of the renewable grid was that the answer could finally be “less.” Whether that promise is kept will depend not only on how much clean power India can generate, but on whether it learns to store that power on its own scientific and industrial foundations — or hands the keys, once again, to someone else.