Offgrid Energy Labs: India-Developed ZincGel Batteries Target the Long-Duration Energy Storage Market

India’s rapid expansion of solar and wind power is creating a second challenge alongside renewable-energy generation: how to store large amounts of electricity for many hours and release it after the sun sets or when wind generation falls.

Lithium-ion batteries already perform this role across thousands of battery energy storage projects worldwide. However, lithium-ion chemistry was initially optimised for applications where high energy density is crucial, such as smartphones and electric vehicles. Grid-scale storage has a different set of priorities. Large stationary batteries can afford to occupy more space, but they must operate repeatedly for years, withstand deep discharge cycles, remain safe around industrial installations and deliver electricity at competitive lifetime costs.

Indian deep-tech company Offgrid Energy Labs is developing an alternative specifically for this market.

Incubated at IIT Kanpur, Offgrid has developed a proprietary zinc-bromide battery platform called ZincGel®. The technology is designed to store electricity for roughly six to sixteen hours without using lithium, cobalt, nickel or rare-earth materials.

The company is now moving beyond laboratory development. In July 2026, it launched a 10 MWh pilot manufacturing facility in Hook, Hampshire, in the United Kingdom, representing the first commercial-scale manufacturing step for its India-developed battery technology. At the same time, Offgrid is working toward eventual gigawatt-scale manufacturing in India.

For India, the significance goes beyond another battery startup. ZincGel represents an attempt to build an indigenous energy-storage chemistry around materials that could offer a different supply-chain and safety profile from conventional lithium-ion systems.

From IIT Kanpur Research to an Indian Battery Company

Offgrid Energy Labs was co-founded in 2018 by Tejas Kusurkar, Brindan Tulachan, Rishi Srivastava and Ankur Agarwal after emerging from the Startup Incubation and Innovation Centre at IIT Kanpur.

The company began with a fundamental question: could stationary energy storage use a chemistry better suited to grids and renewable power than batteries designed primarily around mobility and portable electronics?

That research eventually produced ZincGel.

Offgrid describes itself as a deep-science battery company rather than simply a battery-pack assembler. Its intellectual-property portfolio now includes more than 25 patent families and over 50 IP assets covering electrolytes, electrodes, cell architecture and manufacturing processes across markets including India, the United States, United Kingdom, Europe, China, Japan and Australia.

This distinction is important for India’s manufacturing ecosystem. Building battery packs from imported cells creates manufacturing activity, but controlling the underlying chemistry, materials and cell design creates considerably more technological depth.

What Is a Zinc-Bromide Battery?

Zinc-bromide batteries use electrochemical reactions involving zinc and bromine to store and release electricity.

During charging, electrical energy drives chemical reactions inside the battery. Zinc is deposited at one electrode while bromine-related species form at the other. When the battery discharges, the reaction reverses and releases electrical energy back into the circuit.

Zinc-bromine chemistry itself is not new. Researchers and companies have studied different forms of zinc-bromine batteries for decades, particularly for stationary storage.

Offgrid’s innovation lies in how it manages the electrolyte, electrodes, cell architecture and manufacturing system.

The company calls its technology ZincGel because its proprietary electrolyte system changes how the active materials behave inside the battery. Offgrid describes the electrolyte as one of the central elements of its intellectual property.

Rather than trying to compete directly with lithium-ion batteries in electric cars, laptops or smartphones, Offgrid is concentrating on applications where batteries remain stationary and must deliver electricity continuously for several hours.

Designed for Six to Sixteen Hours of Storage

One of ZincGel’s defining characteristics is its targeted discharge duration.

Offgrid says its current technology has been designed for approximately six to sixteen hours of energy storage.

That places it in the increasingly important category known as long-duration energy storage, or LDES.

Consider a large solar farm. Electricity production rises through the morning, peaks during daylight and drops sharply as evening approaches. Electricity demand, however, does not necessarily follow the same curve.

A storage system can absorb surplus solar electricity during the day and deliver it through the evening and night.

Four-hour lithium-ion systems already perform this task in many markets. As renewable penetration rises, however, grids may increasingly require systems that can shift much larger quantities of electricity across six, eight, ten or more hours.

Offgrid is positioning ZincGel for precisely this window.

Its target applications include renewable-energy projects, industrial facilities, data centres and remote microgrids.

A Battery Without Lithium, Nickel or Cobalt

ZincGel’s chemistry does not depend on several of the minerals commonly associated with modern lithium-ion batteries.

Offgrid says its system contains no lithium, cobalt, nickel or rare-earth elements. Instead, its core chemistry relies on zinc, bromine and carbon-based materials.

That does not automatically make one technology superior to another. Lithium-ion cells possess major advantages, including enormous manufacturing scale, mature global supply chains, high efficiency and excellent energy density.

For stationary storage, however, energy density is less decisive than it is inside an electric vehicle.

A battery installation beside a solar farm does not need to be light enough to move down a highway. A slightly larger battery can remain commercially attractive if its materials, lifetime, safety characteristics and manufacturing economics compensate for the additional space.

This changes the competitive equation and creates opportunities for alternative chemistries.

Zinc and Bromine Create a Different Supply-Chain Opportunity

Offgrid emphasises that zinc and bromine are relatively abundant industrial materials with existing global supply chains.

The bromine component is particularly interesting from an Indian manufacturing perspective.

In September 2025, Offgrid raised $15 million in Series A financing, led by Archean Chemical Industries, with participation from existing investor Ankur Capital. Offgrid had earlier received seed investment led by Shell Ventures.

Archean is a major producer of bromine and bromine derivatives. Its involvement therefore creates more than a conventional investor-startup relationship. The chemical producer can potentially become part of the upstream material supply chain as ZincGel production expands.

Offgrid and Archean have explicitly described this partnership as combining battery intellectual property with experience in large-scale chemical manufacturing.

That type of vertical connection could become important if India seeks to manufacture alternative battery chemistries at gigawatt-hour scale.

Water-Based Electrolyte Changes the Safety Equation

Battery safety is another major part of Offgrid’s pitch.

ZincGel uses a water-based electrolyte, which the company describes as non-flammable and non-explosive.

Conventional lithium-ion battery systems rely on organic electrolytes that can burn under certain failure conditions. Modern battery packs incorporate extensive safety systems to minimise this risk, but thermal runaway remains an important engineering consideration for large installations containing thousands of cells.

An aqueous battery avoids the same type of flammable organic electrolyte.

This could prove particularly useful for stationary systems installed near factories, data centres, commercial buildings or densely occupied areas.

It may also reduce some of the cooling and fire-suppression requirements surrounding large energy-storage systems. Offgrid says ZincGel can operate stably at elevated temperatures and is intended to reduce HVAC requirements and associated operating expenditure.

For a hot country such as India, thermal management can significantly affect the economics of a battery installation.

100% Depth of Discharge

Offgrid also lists 100% depth of discharge as one of the characteristics of its zinc-bromide chemistry.

Depth of discharge describes how much of a battery’s stored energy can be removed before it needs to recharge.

For example, a 100 MWh battery that routinely operates only between 10% and 90% state of charge effectively has less usable energy than its nominal capacity suggests.

A chemistry capable of repeatedly using its full rated storage capacity could therefore improve asset utilisation.

As with all emerging battery systems, however, long-term commercial performance ultimately has to be demonstrated across thousands of operating cycles under real grid conditions.

Pilot projects and early commercial installations will therefore be important for proving ZincGel’s durability.

An All-Carbon Electrode

Offgrid has also developed what it describes as an all-carbon, graphite-free electrode system.

The company lists its electrode chemistry alongside the proprietary electrolyte as one of ZincGel’s major innovation areas.

This approach is significant because graphite has become an increasingly strategic battery material.

Reducing dependence on specialised battery-grade graphite could further diversify the supply chain and simplify sourcing.

The company is not merely substituting zinc for lithium while leaving the remainder of conventional cell architecture unchanged. It is attempting to redesign multiple components of the battery around the requirements of stationary storage.

Static Architecture Instead of Conventional Flow Batteries

Many zinc-bromine batteries historically used flow-battery architectures.

In a conventional flow battery, liquid electrolytes are stored in external tanks and pumped through an electrochemical stack. One advantage is that energy capacity can often be expanded by increasing the amount of electrolyte.

However, pumps, plumbing, tanks and associated balance-of-plant equipment make these systems mechanically more complicated.

Offgrid has instead developed a static-cell architecture.

The company describes ZincGel as a modular battery that does not require the same type of circulating electrolyte infrastructure found in traditional flow batteries. Its proprietary electrolyte helps immobilise the active chemistry inside the cell.

This could potentially make zinc-bromide technology easier to package into conventional battery modules and containers.

It also creates opportunities to use familiar battery-manufacturing processes rather than constructing large chemical circulation systems at every installation.

Manufacturing Could Be Less Capital Intensive

Battery manufacturing economics are often dominated by enormous gigafactories.

Modern lithium-ion production involves highly specialised electrode coating, drying, formation and environmental-control equipment. Achieving competitive costs normally requires immense manufacturing volume.

Offgrid believes ZincGel can follow a different model.

The company says its batteries use simpler manufacturing processes and can be produced through qualified manufacturing partners rather than depending exclusively on highly capital-intensive dedicated gigafactories.

This could allow production to expand through a distributed manufacturing network closer to end markets.

Whether ZincGel can ultimately achieve lower manufacturing costs than mature lithium-ion technology will depend on commercial scale, production yields, materials prices, system lifetime and installation costs.

The important point is that Offgrid is designing manufacturability alongside chemistry rather than treating manufacturing as a later problem.

A 10 MWh Manufacturing Line Marks the Next Stage

The company reached an important milestone on July 7, 2026, when it announced the launch of its first ZincGel manufacturing facility at Hook in Hampshire, United Kingdom.

The facility contains a 10 MWh pilot production line and represents the transition from laboratory-scale development toward commercial manufacturing.

Offgrid describes the plant as a demonstration and validation platform that will allow the company to refine manufacturing, supply batteries for customers and gather operating data before moving toward much larger production volumes.

This is a familiar pathway for deep-tech manufacturing.

A Gigawatt-Scale Plant Is Planned for India

Offgrid’s longer-term manufacturing strategy brings the story back to India.

When announcing its Series A funding, the company said the UK demonstration line would help establish the blueprint for a future GW-scale manufacturing facility in India.

If that plan progresses, India would host commercial-scale manufacturing of an energy-storage chemistry developed by an Indian deep-tech company rather than merely producing licensed foreign battery cells.

That difference matters.

The intellectual property, electrolyte formulation, electrode architecture and manufacturing processes could remain part of an Indian-controlled technology platform even as manufacturing expands internationally.

This is increasingly how successful deep-tech companies operate: research and intellectual property originate in one country while manufacturing and commercial operations expand close to customers around the world.

Storing India’s Solar Power After Sunset

Renewable-energy integration is perhaps the clearest application for ZincGel.

India can install enormous quantities of solar generation, but solar panels produce nothing at night.

Without sufficient storage, grids must compensate using hydroelectricity, coal, gas, nuclear power or power imported from other regions.

A six-to-sixteen-hour battery could change how renewable power plants operate.

A solar project could charge batteries during periods of high irradiation and continue supplying electricity through evening peak demand. Wind projects could store electricity during periods of strong generation and release it when output falls.

Large hybrid projects combining wind, solar and storage could move closer to supplying dispatchable renewable electricity rather than intermittent electricity.

Offgrid describes this renewable-energy shifting application as one of ZincGel’s primary target markets.

Industrial Plants Could Reduce Fossil-Fuel Backup

Industrial users form another important market.

Factories increasingly install captive renewable-energy systems to reduce electricity costs and carbon emissions. However, intermittent generation means many facilities still depend on the grid, diesel generators or other backup sources when renewable output falls.

Long-duration batteries could absorb inexpensive renewable electricity and release it throughout periods when renewable generation is unavailable.

Offgrid is targeting ZincGel at industrial decarbonisation projects where batteries could reduce dependence on fossil-fuel backup systems.

This application may be especially attractive for industrial clusters with large rooftop solar installations or dedicated renewable-energy projects.

Data Centres Need Increasing Amounts of Reliable Power

India’s growing data-centre industry creates another potential market.

Data centres cannot tolerate unexpected power interruptions. They therefore rely on multiple layers of redundancy, including grid connections, uninterruptible power systems and diesel generators.

At the same time, artificial-intelligence computing is dramatically increasing electricity consumption within digital infrastructure.

Offgrid sees ZincGel as a possible long-duration storage system for data centres, helping manage peak electricity demand while reducing dependence on diesel backup.

Battery safety could be particularly valuable here because very large storage systems may operate close to expensive computing infrastructure.

Microgrids Could Replace Diesel in Remote Areas

Offgrid’s original vision also included decentralised electricity.

Remote communities, islands, mines, telecom sites and industrial facilities frequently rely on diesel because transporting grid electricity to these locations is difficult or uneconomic.

Solar generation can reduce diesel consumption, but without adequate storage a generator may still have to operate after sunset.

A long-duration battery coupled with solar or wind generation could significantly extend the number of hours for which these facilities operate without fossil fuels.

Offgrid therefore identifies remote microgrids as another target market for ZincGel.

For India, this could become relevant in remote Himalayan areas, islands, mining regions and locations where extending conventional grid infrastructure remains expensive.

India Will Need Storage on an Enormous Scale

The timing of Offgrid’s technology is significant because India’s electricity system is changing rapidly.

As renewable capacity rises, storage increasingly becomes an essential part of the grid rather than an optional accessory.

Offgrid’s 2025 funding announcement cited projections that India could require more than 236 GWh of battery energy storage by 2032, within a broader storage requirement exceeding 400 GWh.

Lithium-ion will remain extremely important, particularly for shorter-duration storage and applications that value compact size and high efficiency. Pumped hydro will provide massive long-duration storage where geography permits. Other emerging technologies include sodium-ion, iron-air, vanadium flow, thermal storage and several zinc-based systems.

ZincGel is competing to become one part of this increasingly diverse storage ecosystem.

Building Battery Technology Instead of Importing It

The strongest Make in India aspect of Offgrid Energy Labs is the ownership of the technology itself.

India currently imports substantial portions of the advanced battery value chain. Even as domestic lithium-ion cell manufacturing expands, access to lithium, nickel, cobalt, graphite and battery-processing technology remains strategically important.

Alternative chemistries provide another path.

Instead of attempting only to recreate today’s dominant battery industry, Indian companies can develop technologies around materials and applications where the global market is still taking shape.

Offgrid began at IIT Kanpur, developed proprietary electrolyte chemistry, created its own electrode and cell architecture, built an international intellectual-property portfolio and has now reached pilot manufacturing.

From Indian Laboratory to Global Energy Infrastructure

Offgrid Energy Labs illustrates a broader shift in India’s technology ecosystem.

The country is increasingly producing companies that do not merely provide software or assemble imported hardware. They are developing new materials, manufacturing processes and physical technologies capable of competing in global industrial markets.

ZincGel is one such attempt.

Its zinc-bromide chemistry avoids lithium, cobalt, nickel and rare-earth materials. Its water-based electrolyte targets improved fire safety. Its static architecture seeks to simplify traditional zinc-bromide battery systems, while its six-to-sixteen-hour discharge window places it squarely in the emerging long-duration storage market.

The company has already moved from IIT Kanpur research to a commercial pilot manufacturing line in Britain and is working toward much larger manufacturing capacity, including a planned gigawatt-scale facility in India.

ZincGel can become competitive for renewable-energy shifting, industrial power, data centres and remote microgrids.

For India, that would represent something more valuable than assembling another imported battery design. It would mean taking energy-storage technology conceived in an Indian research ecosystem, developing the intellectual property domestically and scaling it into an industrial platform capable of serving power grids around the world.

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