Solar’s Half-Built Bridge, Why India’s Battery Storage Gap Threatens Its Clean Energy Future
India scaled a record peak demand of 256.1 GW on April 25, with solar plants supplying 21.5 per cent of the afternoon load—an all-time high, and the clearest signal yet that the country’s installed solar fleet can do real work when the sun is overhead. It was a moment of celebration for India’s renewable energy sector, a validation of years of investment, policy support, and technological advancement. But the same day’s full 24-hour ledger told a more sobering story.
When accounting for the whole day of April 25, solar contributed only about 10.8 per cent of daily generation, and just 0.1 per cent of the evening’s needs after sunset. The sun sets every day. The evening peaks every night. And without the ability to store the energy generated during the day for use after dark, India’s solar revolution remains a half-built bridge.
This article examines the gap between India’s solar installed capacity and its actual contribution to generation, the critical bottleneck of battery storage, the economic and grid stability consequences of curtailment, the encouraging trends in battery economics, and the urgent policy actions needed to pair every solar auction with mandatory co-located storage.
Part I: The Capacity-Generation Disconnect – What the Numbers Reveal
Solar’s share of India’s installed electric capacity has nearly doubled, from about 15 per cent in 2022 to nearly 28 per cent in early 2026. This is a remarkable achievement. India has added gigawatts of solar capacity at a pace few countries have matched. Fields of photovoltaic panels now stretch across Rajasthan, Gujarat, Karnataka, Tamil Nadu, and other sun-rich states.
However, solar accounted for roughly 5.6 per cent of generation on India’s peak-demand day in 2022 and only increased to the 10.8 per cent of April 2026. In other words, while installed capacity has nearly doubled its share, the contribution to actual generation on peak days has only increased by about 5 percentage points. The gap is not small; it is a chasm.
The bottleneck is not panels, land, or ambition. India has proven that it can manufacture, finance, and install solar capacity at scale. The bottleneck is battery storage—the inability to use the vast stores of generated electrons through batteries. Without storage, solar generation is available only when the sun shines. It cannot meet evening peaks, cannot provide baseload power, and cannot replace conventional generation on a 24-hour basis.
Part II: The Curtailment Crisis – Wasting Power While Paying for It
The paucity of battery storage has led to a perverse outcome: states that are prolific producers of solar power are being asked to halt their supply, lest it compromise the stability of India’s electric grid. The grid cannot absorb unlimited solar power during the middle of the day if there is no demand. Without storage to soak up the excess, grid operators have no choice but to curtail—turn off—solar generation.
In 2025, India had to curtail 2.3 terawatt hours (TWh) of solar generation between late May and December, equivalent to 18 per cent of average monthly solar output. In October alone, 0.9 TWh was wasted. To put these numbers in perspective: 2.3 TWh is enough to power millions of homes for months. It is energy that was generated, transmitted, and then thrown away.
Given that producers of such electricity must be compensated under power purchase agreements, curtailment ends up being a cost to the public exchequer. The government pays for power that was never delivered. It is a double loss: wasted clean energy and wasted public money.
The India Meteorological Department’s forecast of a below-normal monsoon at 92 per cent of the Long Period Average—the first such warning in 11 years—only sharpens the argument. A hotter, drier summer means greater daytime demand for cooling, which is precisely when solar should be doing the heavy lifting. But without storage, the gains are partial at best.
Part III: The Evening Peak Problem – Solar’s Fatal Hour
The most critical vulnerability is the evening peak. Every day between 6 PM and 9 PM, as the sun sets and households turn on lights, fans, televisions, and air conditioners, demand surges. On April 25, after sunset, solar contributed just 0.1 per cent of the evening’s needs. This is not a one-day anomaly; it is the daily reality of un-stored solar.
To replace conventional generation—coal, gas, hydro—for evening peaks, India needs massive battery storage capacity charged during the day and discharged after dark. Battery storage is the bridge that turns solar from an intermittent source into a dispatchable, reliable source. Without it, solar can only ever be a partial contributor.
This is not an argument against solar. It is an argument for completing the investment. Solar without storage is like a dam without a reservoir: it generates power when the river flows, but cannot store it for dry seasons. India has built the dam. It now needs the reservoir.
Part IV: The Encouraging News – Battery Economics Are Falling
The good news is that battery economics are moving in the right direction. Standalone two-hour battery storage tariffs fell from around ₹2.21 lakh per megawatt per month in early 2025 to ₹1.48 lakh by the end of the year. That is a decline of approximately 33 per cent in a single year.
Falling battery prices are driven by global overcapacity in lithium-ion cell manufacturing, technological improvements, and economies of scale. As India ramps up its domestic battery manufacturing capacity under the Production Linked Incentive (PLI) scheme for advanced chemistry cells, prices are expected to fall further.
Lower tariffs make storage economically viable. There is now a business case for pairing solar plants with batteries. The challenge is no longer technological or economic in the abstract; it is about execution.
Part V: The Execution Challenge – From Tendering to Commissioning
Despite falling costs, the actual deployment of battery storage has been painfully slow. Only 0.7 GWh (gigawatt-hours) of battery storage was operational in India by the end of 2025. Another 2 GWh is expected by December 2026. To put this in perspective, India’s solar capacity is measured in hundreds of gigawatts. Storage is measured in single-digit gigawatt-hours. The ratio is wildly imbalanced.
The challenge is not tendering. The government has issued numerous tenders for storage capacity. The challenge is commissioning—actually building the projects, connecting them to the grid, and making them operational. Projects that win bids at aggressively low tariffs often face financing difficulties. Lenders are wary of new technologies, uncertain revenue streams, and counterparty risks. The gap between a signed power purchase agreement and a commissioned battery is where projects go to die.
The Centre and states must now focus less on tendering and more on commissioning. This means resolving the financing wall facing aggressively bid low-tariff projects, providing credit enhancement mechanisms, and ensuring that state distribution companies honour their payment obligations.
Part VI: The Policy Prescription – Pairing Solar with Storage
The most concrete policy recommendation is simple and direct: pair every fresh solar auction with mandatory co-located storage. No new solar project should be approved without a battery component sized to store at least a significant fraction of its generation for evening use.
This is not a radical idea. Several countries, including China, the United States, and Australia, have implemented similar requirements. In India, some states have begun experimenting with hybrid solar-storage tenders. But the policy needs to be scaled nationally, urgently, and with teeth.
Co-located storage reduces transmission costs, simplifies grid integration, and ensures that the storage is actually used. It is far more efficient than building standalone storage projects that may be located far from the solar plants they are meant to complement.
The economics are increasingly favourable. With battery storage tariffs at ₹1.48 lakh per MW per month and falling, pairing solar with storage adds a manageable cost premium while delivering enormous grid reliability benefits. The alternative—continuing to curtail solar generation—is economically wasteful.
Conclusion: Completing the Bridge
India’s solar journey has been remarkable. From negligible capacity two decades ago to nearly 30 per cent of installed capacity today, the country has proven that renewable energy can be deployed at scale, at low cost, and with strong political support. The record peak demand of 256.1 GW, met with 21.5 per cent solar during the afternoon, is a milestone worth celebrating.
But a milestone is not a destination. The same day’s ledger—10.8 per cent of daily generation, 0.1 per cent after sunset—reveals the unfinished work. Solar capacity without storage is a half-built bridge. It carries traffic during the day but leaves commuters stranded at night.
Battery economics are falling. The technology is ready. The policy tools are available. What is needed now is the political will and administrative focus to move from tendering to commissioning, from ambition to execution. Every fresh solar auction must be paired with mandatory co-located storage. The financing wall must be breached. And the curtailment of solar generation—wasting clean energy while paying for it—must become a distant memory.
India has built the solar fields. Now it must build the batteries. The bridge is half-built. It is time to complete it.
5 Questions & Answers Based on the Article
Q1. What record did India achieve on April 25, 2026, and what does it reveal about solar’s potential?
A1. On April 25, 2026, India scaled a record peak demand of 256.1 GW. Solar plants supplied 21.5 per cent of the afternoon load—an all-time high. This is the clearest signal yet that India’s installed solar fleet can do real work when the sun is overhead, validating years of investment and policy support. However, the achievement also reveals the critical gap caused by lack of storage, as solar’s contribution dropped to just 0.1 per cent after sunset.
Q2. What is the gap between solar’s installed capacity share and its actual generation share?
A2. Solar’s share of India’s installed electric capacity has nearly doubled from about 15 per cent in 2022 to nearly 28 per cent in early 2026. However, solar accounted for only about 5.6 per cent of generation on India’s peak-demand day in 2022 and increased to only 10.8 per cent in April 2026. This gap reveals that installed capacity does not translate into commensurate generation because solar generation is limited to daytime hours and cannot be stored for evening use.
Q3. How much solar generation was curtailed in 2025, and why is this a problem?
A3. In 2025, India had to curtail 2.3 terawatt hours (TWh) of solar generation between late May and December, equivalent to 18 per cent of average monthly solar output. In October alone, 0.9 TWh was wasted. This is a problem because curtailment means clean energy is thrown away, and producers must still be compensated under power purchase agreements, making it a cost to the public exchequer—wasted energy and wasted public money.
Q4. How have battery storage tariffs changed, and what is the current operational storage capacity in India?
A4. Standalone two-hour battery storage tariffs fell from around ₹2.21 lakh per MW per month in early 2025 to ₹1.48 lakh by the end of the year—a decline of approximately 33 per cent in a single year, driven by global overcapacity, technological improvements, and economies of scale. However, only 0.7 GWh of battery storage was operational in India by end-2025, with another 2 GWh expected by December 2026. This is minuscule compared to India’s solar capacity, which is measured in hundreds of gigawatts.
Q5. What is the article’s key policy recommendation for future solar projects?
A5. The article’s key policy recommendation is to pair every fresh solar auction with mandatory co-located storage. No new solar project should be approved without a battery component sized to store at least a significant fraction of its generation for evening use. Co-located storage reduces transmission costs, simplifies grid integration, and ensures storage is actually used. The alternative—continuing to curtail solar generation—is economically wasteful. The article concludes that “solar capacity without storage is a half-built bridge.”
