Rainmatter’s climate and deep tech investments

Rainmatter is Zerodha’s fund for fintech, health, climate and deep tech. This is how we think about the climate and deep tech side of it.

A note on what this is, before we get into it. Venture funds write investment theses because they have Limited Partners (LPs) (the institutions and individuals whose money a fund manages) to convince and a fund cycle to justify. We have neither. Rainmatter invests Zerodha’s own capital, which means there is no fund to raise, no deployment clock, and no pressure to have a neat answer for every sector. What we have instead is a direction: a set of problems we keep getting pulled towards, and the founders we have backed along the way. So treat this post accordingly. It is not a framework. It is a map of our conviction as it stands today, and it will change as we learn.

That direction points at climate and deep tech because we think they are where the most consequential businesses of the next two decades will be built. And the same fact, that the capital is our own, is why we are a relevant backer here.

These businesses take a long time to build, and most institutional capital comes with exit pressure and return timelines that simply do not fit the work. We are a perpetual fund with no exit mandates, which means we can back founders for as long as the work demands, without forcing decisions that are good for a fund cycle but bad for the business. That is the actual differentiator and the reason founders in these spaces talk to us.

We started with Rainmatter Foundation on the non-profit side, then moved into investing in climate, and subsequently into deep tech.

The move into deep tech was a natural extension and not a separate decision. When you back companies in climate and health at any depth you quickly find yourself in physical systems, materials science and sensing technology. The line between climate and deep tech is blurry and we stopped trying to enforce it.

India has the problems, the talent and increasingly the policy support. The fact that many of the best founders in these spaces have had to raise abroad is a symptom of an ecosystem that has not caught up. That is changing and we want to be part of that change.

The sectors that attract the least capital tend to produce the most technically rigorous founders. As we spent time with some of these founders we learnt about deployment challenges, about the gap between what a pilot proves and what scale demands, about holding a team together through a long validation cycle. These are the biggest problems both climate and deep tech face.

Focus on manufacturing

Most of what these founders are building is physical: systems, materials, hardware and infrastructure. That is not coincidental. It reflects something we believe more strongly with every passing year: India’s next chapter has to be manufacturing.

India grew on services. That chapter is not over but its ceiling is clearer than it has ever been. In an era where AI can do a significant chunk of what large IT services franchises charge for, the honest question is who pays top dollar for that work in a world where software is increasingly commoditised. When a single model update can absorb an entire product category, software alone is a fragile moat. The next chapter has to be making things.

The China plus one moment is real, indigenisation mandates are creating structural demand that did not exist five years ago, and the policy intent to back domestic manufacturing is stronger than it has been in decades. This is our moment to build an economy that actually makes things, and this window will not stay open indefinitely.

Contract manufacturing for a known part is largely a solved problem; India has capable shops. The harder problem is the component that does not exist in India at all: a hydraulic pump still sourced from Russia and Ukraine, a renewable energy part still imported, an EV drivetrain with no indigenous Intellectual Property (IP). Building these requires sustained engineering work upstream of manufacturing: design, prototyping, validation, and the patience to fail through iterations. Very few companies in India do this work, and fewer still at scale. That is the gap we are most interested in, and Naxatra Labs and Ergon Labs show what closing it looks like.

India sold 2.3 million EVs in 2025 but the powertrain electronics inside most of them barely evolved as the market grew tenfold. Naxatra Labs manufactures high-efficiency motors using axial and radial flux technology, having taken multiple products from Research and Development (R&D) to production. Ergon Labs has combined the on-board charger and motor controller into a single unit, enabling fast charging without dedicated infrastructure.

There is also a discovery problem sitting underneath all of this. India has hundreds of capable Micro, Small and Medium Enterprises (MSMEs) running below capacity, while startups and large enterprises looking to indigenise their content struggle to find them. Venttup connects the two, turning underutilised MSME capacity into a distributed manufacturing network. Indigenisation mandates are creating the demand; someone has to organise the supply side, and that is what Venttup is building.

Making things is only half the story; moving them efficiently is the other. MatchLog eliminates the empty container runs that every import-export cycle in India currently wastes, by matching containers from the hinterland to their next load instead of sending them back empty. If India is going to trade more with the world, this is the kind of unglamorous efficiency that compounds.

Bioenergy and biochemicals

Another sector that really excites us is bioenergy and biochemicals. Every hundred years or so the dominant energy paradigm shifts. Coal was the 19th century, oil and gas were the 20th, and we think this century belongs to biological energy and biological materials.

India is abundant in biomass and almost none of it is being converted into fuel, chemicals, or materials at the scale it could be. The Liquefied Petroleum Gas (LPG) shortage in Bengaluru earlier this year, briefly threatening restaurant shutdowns across the city, was a reminder of how fragile energy supply chains can be and how much of the solution is sitting in our own backyard.

Greenjoules makes second-generation biofuels from agricultural residues and food industry waste, producing drop-in renewable fuel that works in existing diesel engines without modification. That last part matters. India’s diesel demand is not going away this decade, and fuels that require no new engines and no new infrastructure are the fastest route to displacing fossil molecules in transport and industry.

FarmWatt is creating the agri feedstock supply chain for our country’s biogas plants. AltMat turns crop residue that would otherwise be burned into natural cellulose fibres, with global apparel and home brands already buying at industrial volumes. altM goes a level deeper into the same feedstock. Its biorefinery first deconstructs agricultural residue into its molecular building blocks of cellulose, hemicellulose, lignin, and silica, then upgrades those fractions into speciality chemicals and materials that replace petrochemical-derived ingredients across cosmetics, packaging, textiles, and industrial chemicals. The science of bio-based materials is decades old; making them at industrial scale and competitive cost has always been the hard part, and that is the layer altM is building. Carbon Masters converts urban organic waste into compressed biogas and fertilizer across three states. Amwoodo makes bamboo-based alternatives to single-use plastics, working with farmers and artisans across the northeast and already exporting to six countries.

The common thread is India’s biomass abundance and the conviction that it is one of our most underutilised assets.

Power and storage

SolarSquare is making residential solar straightforward, but generation without storage is only half the problem. Energy storage is therefore a natural focus area for us. Voltanova is building thermal battery storage for industrial decarbonisation, and Delectrik is working on what may be the most urgent structural gap in the energy transition: India has over 250 Gigawatts (GW) of installed renewable capacity but less than 1 Gigawatt hour (GWh) of commissioned battery storage. The Central Electricity Authority (CEA) says we need 411 GWh by 2031-32, roughly a 500x increase in seven years, and right now we are building solar parks and throwing away their output because there is nowhere to put it.

Delectrik makes vanadium redox flow batteries that decouple power and duration, and which the company’s economics show to be cheaper than lithium-ion for the 4-12 hour storage the grid actually needs. VoltSeal is also building energy storage for India, because a gap this large will not be closed by one chemistry or one company. Then there is Anubal Fusion, India’s first nuclear fusion startup, five to ten years from commercialisation at best. We think some problems deserve to be worked on before the market demands it.

Generation and storage are the supply side. SundayGrids widens access on the demand side by letting anyone buy into remote solar and offset their utility bills without owning a roof, and Zodhya cuts electricity consumption of air conditioning systems by 15-20% by regulating their energy intake. The cheapest unit of energy is still the one never consumed. And as EVs become the grid’s newest large load, Numocity builds the software layer that runs charging networks, powering operators across more than 15 countries from India, a rare case of Indian energy infrastructure software going out to the world.

None of this gets built without money moving, and climate projects in India stall as often for lack of financing as for lack of technology. Neufin is building the platform that connects green projects to lenders, making it easier for capital to find the solar rooftop, the EV fleet, or the efficiency retrofit that needs it.

Material science

Materials is an area where our conviction is building but our portfolio is still forming. Every time we go deep into a problem in climate or industry, we find someone working on a new material or a new process that is central to the solution. We keep meeting founders operating at the intersection of biology, chemistry, and engineering, each approaching a different part of the same underlying problem: India generates enormous volumes of waste and uses enormous volumes of virgin materials, and almost nothing flows between the two.

PolyCycl converts hard-to-recycle plastics into hydrocarbon oils via chemical recycling after over a decade of R&D. Apratima Biosolutions uses AI-engineered enzymes to break Polyethylene Terephthalate (PET) (the plastic used in bottles and textiles) down to its molecular building blocks, a completely different angle on the same circularity problem. 

Zerocircle makes seaweed-based films, coatings, and papers that replace petrochemical plastics in food packaging, the burger boxes, fried food containers, and coated paperboards that plastic bans are pushing out of the market. Seaweed is a remarkable feedstock: it needs no freshwater, no fertiliser, and no land, and the materials made from it are home-compostable rather than needing industrial facilities to degrade. Just as important, Zerocircle has engineered its materials to run on existing packaging lines, so converting to seaweed does not mean rebuilding the factory. Karo Sambhav is working on e-waste recycling at scale. 

CarbonStrong takes the waste-to-virgin-materials problem into construction, converting processed fly ash into a low-carbon binder that the company says can replace 40-50% of the cement in concrete as a drop-in, at lower cost. Cement is one of the largest single sources of industrial emissions in the world, and India is its second-largest producer, so the leverage here is enormous.

Econovus builds sustainable industrial packaging that cuts carbon footprint while also cutting cost. Packaging is an unglamorous but essential layer of the manufacturing story: if India is going to make and export more, everything it makes has to travel, and global buyers increasingly want that to happen in packaging that is both cost-competitive and low-carbon. Dharaksha attacks two problems with one product, making biodegradable packaging material from crop stubble that would otherwise be burned.

Minimac has built a business in industrial oil purification with a clear thesis around decarbonising the lubricant lifecycle. Ossus Biorenewables uses waste carbon in industrial effluents to produce green hydrogen on-site. NoPo Nanotechnologies manufactures Single-Walled Carbon Nanotubes (SWCNTs) (cylinders of carbon one atom thick, among the strongest and most conductive materials known) at high purity, placing India in a very small global club in a field otherwise dominated by a handful of large international producers.

Materials like these sit upstream of everything from better batteries to lighter structures, exactly the kind of foundational capability India has historically imported rather than built. We expect this part of the portfolio to keep growing as we meet more people working in this space.

Circularity in India is not just a technology problem, it is a livelihood problem, because millions of people already do this work informally and invisibly. Green Worms and Hasiru Dala Innovations organise waste collection through informal waste pickers, proving that a circular economy and dignified livelihoods are the same project. Wastelink converts commercial food waste into animal feed. Padcare is solving menstrual waste disposal, protecting both the environment and the sanitation workers who otherwise handle it.

Deep Tech

Beyond climate, we are investing in AugSense Labs for quantum sensing and in Quanfluence, which is building photonic quantum computing and already has an optimisation platform with paying customers. AstraYAN is building software for autonomous vessel operations in a sector almost entirely dependent on imported technology.

In space, GalaxEye is building multi-sensor earth observation satellites fusing Synthetic Aperture Radar (SAR) (radar imaging that works through clouds and darkness) with optical imagery, and Agnikul is building small launch vehicles around single-piece 3D-printed rocket engines, compressing what used to take months of precision manufacturing into days.

SpaceFields builds solid rocket propulsion systems for defence and space, and has hot-fired India’s first aerospike rocket engine, supplying indigenous propulsion to the armed forces, defence research organisations, and drone makers who until now had nowhere domestic to buy it from.

In autonomous aerial systems, Vecros builds drones that navigate using spatial AI rather than GPS, which means they keep working in the places where inspection is hardest and jamming is likeliest: tunnels, warehouses, dense infrastructure, contested airspace. AquaAirX is building amphibious autonomous systems that transition between aerial and underwater operation. BluJ Aero is building hydrogen-electric Vertical Take-off and Landing (VTOL) aircraft for cargo, betting that the future of moving goods through the air will not run on batteries alone. All three are working on the same underlying problem of machines that can perceive and act in the physical world without a human pilot or an external signal.

India has always been a large consumer of technology built elsewhere. These deep tech bets are about changing that: India not just using quantum computing, satellite intelligence and autonomous systems but building them, owning the IP, and eventually licensing them to the world. The economic and strategic value of that shift is significant and we think this generation of founders is the one that makes it happen.

The essentials: food, air and water

Then there are the most fundamental things: the food we eat, the water we drink, and the air we breathe.

Food is the most commercially mature of the three. Air and water have longer gestation periods, where the path to scale runs through municipalities, housing societies, and communities rather than quick commercial adoption. The problems are too large and too important to leave unaddressed.

On food, Akshayakalpa, Two Brothers, and Just Organik are recovering dairy and agri-food value chains from commodity markets, building businesses where farmers earn better and consumers know what they are eating. Organic Mandya is mainstreaming organic farming practices with over 7,000 farmers across 270 villages. Raheja Solar attacks food wastage at the farm gate: its foldable solar dryers, paired with a buyback of the dried produce, turn surplus that would otherwise rot into shelf-stable income for farmers. Marin Elixirs makes seaweed-based biostimulants, a natural alternative to chemical fertilisers. And then there is the next generation of the sector itself: Fragaria is building controlled environment farming, and Krop AI is enabling enterprises to own their food sourcing end to end. Both are new-age agriculture companies building what farming in India will look like a decade from now.

Jovaki Agro Food is a good example of what we mean by indigenous food systems. It builds a value chain for Minor Forest Produce (MFP) (non-timber forest produce such as wild fruits, honey, and herbs that forest communities collect for a living), processing wild custard apple and jamun through village units run by tribal women in Rajasthan’s Aravalis. Over 5,000 women across 48 villages now earn from produce that earlier went to waste or to middlemen, and a quarter of the seeds from processing go back into the forest for replantation. Tribal communities are among the most neglected sections of our society, and food systems built around what their forests already produce employ and uplift them while regenerating the ecosystems they depend on.

Fishmongers is doing for aquaculture what these companies are doing on land, building from hatchery to retail with Internet of Things (IoT) pond monitoring and India’s first patented live fish transport system. India produces enormous volumes of fish that mostly move through a system with zero traceability and enormous waste, and Fishmongers is the infrastructure that the sector never had.

On water, if you live in Bengaluru, this will be familiar. The city pumps 1,450 million litres every day from the Cauvery, a river roughly 100 kilometres away and 350 metres below the city’s elevation. The electricity bill just for that pumping is about three crore rupees a day. An estimated 500 million litres more comes from over three lakh borewells across the city, many of which are failing. And yet Bengaluru floods after rain and runs dry in summer.

These are not two separate problems. They are the same broken water system playing out across seasons. The important thing to understand is that this is not primarily a supply problem. It is a management problem. The infrastructure exists. What is missing is data, monitoring, and the ability to act on it before things go wrong.

Across India, an estimated 38% of water that enters the pipe network never reaches its destination, not because there is not enough water but because there is no visibility into where it goes. That visibility is where several of our companies sit. Kritsnam makes smart ultrasonic flow meters and treats water accounting the way finance treats book-keeping: every litre metered, every balance reconciled, every number defensible, which is what regulators and large industrial users increasingly demand. Greenvironment puts real-time IoT monitoring into water facilities, treating water as a system managed through data. Fluxgen is working on industrial water efficiency, helping factories measure and cut their water use. Wattr.ai is building the intelligence layer for water and energy management, treating the two as the linked resource problem they actually are, since so much of India’s water cost is really an energy cost.

Then there is the physical layer. Boson Whitewater converts surplus Sewage Treatment Plant (STP) water into potable water, and JSP Enviro is making secondary water treatment affordable enough to actually get deployed. Solinas uses robotics to inspect pipelines for leaks and clean manholes without human entry, which matters because 330 people died doing that manually between 2017 and 2021.

On air, India has some of the worst air quality in the world and it remains one of the most underinvested problems in the climate space. The sources are diffuse, the measurement infrastructure is thin, and most solutions developed elsewhere were not built for Indian conditions.

Aurassure is building hyperlocal climate intelligence for cities, giving urban managers real-time visibility into air quality and heat at a neighbourhood level. Novorbis Itus is solving air pollution from Diesel Generator sets and crematoriums, two sources that are urgent, undeniable, and that global solutions were simply not designed for. Saroja Earth is taking an R&D-first approach to clean air solutions built for Indian conditions.

What we learnt and what we are still figuring out

We are still figuring out a few of these spaces and are honest about it. The quantum and fusion bets could take longer and require more capital than any current model shows. On the manufacturing thesis, we see the gap clearly but our search for the right engineering-first companies to back at scale is really just beginning. A lot of what we want to invest in here does not exist yet, or exists in a form too early for us to validate. We are working on ways to back companies at that stage and will share updates when things look solid.

One thing has genuinely surprised us through all of this: the quality of what is being built in India.

Spending time with these founders and seeing their work up close has dispelled a lot of myths. The technology is world class, the engineering depth is real, and the ambition is not smaller than anywhere else in the world. The question was never whether India could build these things. It was whether the ecosystem, the capital, and the market timing would come together. They are coming together now and we feel fortunate to have a front row seat to that.

You can find all our portfolio companies mentioned in the piece here: Rainmatter portfolio