India’s energy storage strategy is quietly expanding beyond lithium-ion batteries and pumped hydro as thermal energy storage (TES) enters policy frameworks and corporate investment plans, offering a lower-cost pathway to decarbonize industrial heat and manage grid peaks without critical mineral dependencies. The shift matters because industrial process heat accounts for roughly 30% of India’s final energy demand, and TES can serve that load directly while also providing grid-scale storage at a fraction of battery capital costs per megawatt-hour.
Why Thermal Storage Is Gaining Traction in India’s Policy Circles
For the past decade, India’s storage roadmap has been written around two pillars: lithium-ion for short-duration shifting and pumped hydro for long-duration capacity. The Central Electricity Authority’s 2023 National Electricity Plan targets 41.6 GW of battery storage and 26.7 GW of pumped hydro by 2032. Neither technology, however, addresses the single largest end-use of energy in the Indian economy – industrial process heat – which runs on coal, gas, and biomass today. TES changes that calculus by storing energy in the form it is ultimately consumed.
The mechanics are straightforward: surplus solar or wind electricity heats a medium – molten salt at 565°C, pressurized water at 200°C, or phase-change materials at 120-250°C – which then delivers steam or hot air to a cement kiln, textile dryer, or food-processing line hours later. Round-trip efficiency for power-to-heat-to-power cycles sits at 35-45%, but power-to-heat-to-heat approaches 95%. For a cement plant that needs 150°C air regardless of grid conditions, the latter pathway eliminates the efficiency penalty entirely. That distinction is why the Ministry of Power’s 2024 draft guidelines for energy storage procurement now include TES as a distinct category eligible for capacity payments, and why the Bureau of Energy Efficiency has begun drafting performance standards for industrial TES installations.
Capital cost data from early Indian pilots supports the economic case. A 10 MWh molten-salt system commissioned at a Gujarat textile cluster in 2023 came in at roughly ₹4.5 crore per MWh (about $540/kWh), compared with ₹7-9 crore per MWh for lithium-ion at the same scale. Phase-change material modules deployed at a Maharashtra cold-storage facility achieved ₹3.8 crore per MWh. These figures exclude balance-of-plant and power-conversion equipment, but even with those additions, TES remains 30-50% cheaper per stored megawatt-hour than batteries for durations beyond six hours. The trade-off is lower round-trip efficiency when electricity is the final output – a constraint that matters less when the end use is thermal.
Cross-Cutting Dynamics: Critical Minerals, Grid Flexibility, and the Solar Overbuild
The rise of TES in India cannot be separated from three converging pressures. First, the critical-mineral supply chain. India imports 100% of its lithium, 95% of its cobalt, and 80% of its nickel. The Ministry of Mines’ 2023 Critical Minerals Strategy identifies domestic recycling and overseas offtake agreements as long-term levers, but near-term battery deployment remains exposed to price volatility and geopolitical risk. TES relies on steel, concrete, salt, and sand – materials India produces at scale. That material independence is a strategic asset the government has begun to price into procurement tenders through domestic-content weighting.
Second, the solar overbuild problem. India added 15 GW of solar in FY2024, pushing midday generation above demand in several states during non-harvest months. Curtailment in Tamil Nadu and Rajasthan averaged 4-6% of available solar energy in Q1 2024. Batteries absorb two to four hours of that surplus economically; beyond that, levelized cost of storage rises steeply. TES, with inherent 8-16 hour duration at low marginal cost, becomes the logical sink for the next tranche of midday excess. A 2024 NREL-India joint study modeled a 2030 Rajasthan grid with 60 GW solar and found that adding 10 GW of 10-hour TES reduced curtailment by 62% compared with a battery-only portfolio at equal capital outlay.
Third, industrial decarbonization mandates. The Perform, Achieve, and Trade (PAT) scheme’s current cycle requires designated consumers in cement, steel, and chemicals to improve specific energy consumption by 3-5% over three years. Electrification of process heat via heat pumps hits a temperature ceiling around 200°C; above that, resistance heating or hydrogen are the main electric options, both expensive. TES bridges the gap by letting plants run electric heaters when renewable power is cheap and store the heat for continuous operation. That points to a hybrid model where batteries handle grid frequency and short-duration shifting, while TES absorbs midday solar glut and delivers firm thermal energy to factories – a division of labor that optimizes both cost and mineral use.
Who This Affects
- Utility planner: Model TES as a distinct resource class in integrated resource plans with 8-16 hour duration and 35-45% round-trip efficiency for power-to-power, but treat it as a 95% efficient thermal resource for industrial load – this avoids overbuilding batteries for durations they serve poorly.
- Storage developer: Pursue hybrid projects pairing 2-4 hour lithium-ion with 10+ hour TES at single interconnection points; the battery captures ancillary-service revenue while TES arbitrages daily solar cycles and sells firm heat to adjacent industrial offtakers.
- Policy analyst: Track the Ministry of Power’s forthcoming TES capacity-payment mechanism and BEE’s efficiency standards – these will set the revenue floor and technical baseline that determine bankability for the first utility-scale projects.
- Industrial energy manager: Evaluate TES against green hydrogen and biomass for process heat above 200°C; levelized cost of heat from solar-plus-TES is already competitive with delivered biomass in western India and beats green hydrogen by a factor of three on current electrolyzer costs.
What to Watch Next
- First utility-scale TES capacity auction: The Solar Energy Corporation of India is expected to float a 500 MWh TES tender by Q4 2025; the clearing price and duration requirements will establish the market benchmark.
- PAT cycle compliance filings due March 2026: Disclosures from cement and steel majors will reveal how many designated consumers have adopted TES versus alternative decarbonization levers.
- Domestic molten-salt supply chain: Watch for announcements from Indian salt producers (e.g., Gujarat Heavy Chemicals, Tata Chemicals) on dedicated solar-grade nitrate production – currently imported at $400-500/tonne.
- Grid-code amendments for thermal resources: The Central Electricity Regulatory Commission’s 2025 grid-code review proposes explicit scheduling and ancillary-service rules for TES; finalization will determine whether TES can earn frequency-regulation revenue alongside energy arbitrage.
Bottom Line
Thermal energy storage is not a battery substitute – it is a parallel storage infrastructure that solves a different problem: delivering firm, high-temperature heat to industry while soaking up midday solar surplus at low mineral intensity and low capital cost per megawatt-hour. India’s storage stack will likely stratify into batteries for sub-four-hour grid services, TES for 8-16-hour thermal and power shifting, and pumped hydro for multi-day capacity, with each technology earning its keep in the segment where its physics and economics align.
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Note: facts and figures attributed above to reflect that outlet's original reporting. Broader context, cross-sector connections, and forward-looking scenarios reflect independent analysis by our editorial team.
About this article: Drafted by Energy Ai with AI-assisted research and writing based on public reporting, then reviewed under our editorial process before publication.
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