Startup Deep Dive : Ossus Biorenewables — hydrogen under a dollar a kilo from wastewater, profit still falling

A bioreactor in Jharkhand turns 6,000 litres of steel-plant effluent into about 30 kg of hydrogen a day, and it does the job on roughly a hundredth of the electricity a conventional electrolyser needs. The company behind it, Ossus Biorenewables, says it is the only Indian outfit producing and selling hydrogen from wastewater at under a dollar a kilogram — a bold claim from a nine-year-old firm whose most recent public filing shows profit falling, not rising.

That contradiction is the story. Ossus has real engineering, a working pilot, and backers who write checks after seeing the reactor run. It also has a balance sheet that, on the one year of numbers the Ministry of Corporate Affairs has made public, looks stretched. Both things are true at once, and this piece tries to hold them together with only what could be verified.

Quick facts

What they do

Ossus Biorenewables builds a bio-electrochemical reactor called OB HydraCel that sits inside a factory and eats its wastewater. Electroactive bacteria already present in industrial effluent break down the organic pollutants; the electrons that reaction releases are steered through an electrochemical cell to split water molecules and produce hydrogen, while the effluent itself comes out cleaner and reusable. The company markets this to what it calls hard-to-abate process industries — steel, refining, petrochemicals, brewing, food processing, chemicals and pharmaceuticals — as a way to get carbon-free hydrogen for on-site heat and processes without buying an electrolyser or piping in fresh water. Ossus offers the reactor three ways: it can build and operate the unit itself and sell the client hydrogen and treated water as a service, hand over a turnkey installation, or run a hydrogen-as-a-service model with an EPC partner, according to the company’s own site.

The origin

Ossus was incorporated on 16 October 2017, according to the Ministry of Corporate Affairs record reported by Tofler, though the company’s own website and most trade coverage describe it as a Bengaluru-based startup even though its registered address sits in Mumbai’s Gundecha Towers — the company itself says it is headquartered in Mumbai with a satellite office in Bengaluru, a small inconsistency worth flagging rather than smoothing over. The three founders split the work along predictable lines: Suruchi Rao as chief executive, Shanta Rao as chief legal officer, and Kamar Suhail Basha as chief technology officer, according to The Ken’s Green Margins newsletter. The founding insight, as that reporting lays it out, was simple to state and hard to engineer: industrial wastewater already carries dissolved carbon and a resident population of microbes that can be coaxed into generating an electric current, and that current can do the work a grid-powered electrolyser would otherwise do. Rather than treating effluent purely as a compliance cost to be dumped or filtered, Ossus set out to treat it as a feedstock — one that pays for its own disposal by yielding hydrogen and clean water on the way out.

The struggle years

The public record on Ossus’s early years is thin, but what exists points to a long, quiet grind rather than a straight line. Inc42’s company database describes the venture as having started out with a narrower ambition — converting industrial waste into biofuels — before it expanded into hydrogen production, a pivot away from its original product line that the company does not appear to have publicised with a date attached. What is dated, from the same funding record, is the gap in outside validation: Ossus’s first disclosed capital came from the Shell E4 accelerator around February-March 2018, and the next disclosed institutional event on record did not land until January 2023, when it won a grant from India’s Defence Innovation Organisation under the iDEX programme. Five years between a corporate accelerator ticket and the next confirmed institutional nod, for a deep-tech hardware company trying to commercialise a novel reactor, is itself the story: no near-death is documented in the press, but no funding is documented in that stretch either, and hardware startups do not survive on air. The company’s own financial filings pick up only from FY24, so the years in between are effectively undocumented from outside — the company was, on the public record, invisible.

The turning point

The moment Ossus has something concrete to point to is its steel-plant deployment in Jharkhand, running since 2020. At the scale reported by The Ken in July 2023, the unit was processing 6,000 litres of industrial effluent a day to produce roughly 30 kg of hydrogen — a pilot-sized number that would barely register against an industrial site’s total energy demand. Set against that is what the same reporting says the company was aiming for at full scale: treating 127 cubic metres of effluent to produce 21 tonnes of hydrogen a day, or close to 7,200 tonnes a year, from a single installation. That is roughly a 700-fold jump in daily hydrogen output from the numbers already running on the ground, and it is the gap between those two figures — proven pilot versus stated full-scale target — that defines whether Ossus becomes an infrastructure company or stays a demonstration project. Separately, in its April 2023 fundraise, founder Suruchi Rao told reporters the company was targeting 3-5 tonnes of hydrogen a day by the end of that year, a nearer-term marker that sits between the pilot and the full-scale vision.

The money behind it

Ossus has raised money in small, spaced-out increments rather than one clean growth round, and only one of its rounds carries a disclosed size.

• Pre-seed, around February-March 2018: backed by Shell E4, the oil major’s accelerator programme for energy-transition startups; amount undisclosed (Inc42, CB Insights).
• Grant, January 2023: won a grant from India’s Defence Innovation Organisation through the iDEX (Innovations for Defence Excellence) scheme; amount undisclosed (Inc42).
• Pre-Series A, announced 4-7 April 2023: $2.4 million (about Rs 23 crore, converted at $1 = Rs 96.0 as of 18 September 2026), led by Gruhas with Rainmatter Climate participating, reported consistently by Outlook Business Startup, IndianStartupNews, IamRenew and in Rainmatter’s own investment note on its Grove forum.

That pre-Series A is the only round with a confirmed dollar figure across the sources checked for this piece; other trackers cite a higher lifetime total and a later 2024 round, but those numbers appeared only in aggregator summaries this reporting could not open and verify directly, so they are left out here rather than repeated on trust. What the two named lead backers bring is distinct: Gruhas, the venture platform backed by Nikhil Kamath and Filter Capital’s founders, writes checks into physical, build-heavy businesses rather than pure software; Rainmatter Climate, Zerodha’s climate-focused investment arm, explicitly framed its bet in the Grove note around India’s push to cut electrolyser imports and build indigenous green-hydrogen capacity. Total disclosed funding across all rounds, from the figures this piece could confirm, comes to at least $2.4 million.

How it makes money

The commercial pitch rests on a cost and energy comparison Ossus and its investors repeat consistently across the record:

• Energy intensity: Rainmatter’s investment note (April 2023) cites OB HydraCel at roughly 0.76-8 kWh per kilogram of hydrogen produced, against about 53 kWh/kg for a conventional water electrolyser; a separate account from the Nasscom CoE-IoT writeup and later coverage puts conventional electrolysis at 50-55 kWh/kg — the two figures for the conventional benchmark are close enough to treat as the same claim from different tellings.
• Cost per kilogram: founder Suruchi Rao stated in April 2023 that Ossus was “the only company in India producing and supplying hydrogen at less than a dollar per kilogram using wastewater” (Outlook Business Startup, IndianStartupNews); NatNavi’s account of the same period puts the conventional green-hydrogen benchmark at $4-6/kg for comparison.
• Revenue models: build-own-operate (Ossus owns the reactor, sells hydrogen and treated water as a service), turnkey sale of the installation, and a hydrogen-as-a-service structure run with an EPC partner, per the company’s own website.
• What people get wrong: the product is not simply “hydrogen” — the same unit is also a wastewater treatment plant, and the client’s saving on effluent-treatment cost and freshwater intake is as much a part of the pitch as the hydrogen itself, since the reactor needs no external freshwater input, per Third Derivative’s portfolio description.

Where the margin actually sits — gross margin per kilogram after capital recovery on the reactor, or the split between hydrogen revenue and treatment-fee revenue — is not disclosed in any source available for this piece, and is not invented here.

The numbers

Ossus is a private company and its full financial history is not public. The only fiscal year with disclosed figures is FY24 (year ended 31 March 2024), via an MCA filing reported by Tofler; that record shows movement, not the absolute rupee figures, because the underlying line items sit behind a paid subscription. What is disclosed is directional and blunt:

No FY22, FY23 or FY25 absolute figures could be verified from a source this piece actually opened, so a multi-year revenue trend line is deliberately not presented here — the swings above are the only sourced data point, and they point toward a business that spent FY24 burning capital rather than turning a profit, consistent with a hardware startup still scaling a single flagship deployment rather than running commercial volumes across many sites.

Where the money comes from

Ossus markets itself across a wide industrial waterfront — steel, refining, petrochemicals, food processing, brewing, chemicals and pharmaceuticals are all named as target sectors across its funding announcements and its own website. The surprise, on the public record, is how narrow the proof is next to how wide the pitch is:

• Documented commercial site: a single steel plant in Jharkhand is the only named, operating deployment across every source checked for this piece, running since 2020 (The Ken, July 2023).
• Sectors named as targets but with no confirmed live deployment in the sources checked: refining, petrochemicals, brewing, food processing, pharmaceuticals and general chemicals.
• Geography: every disclosed activity is inside India; expansion into South Asia, Europe and the US was described as a fundraise-stage ambition in April 2023 (IndianStartupNews), not a confirmed operating footprint.

In other words, a company that talks in terms of six industrial sectors and three continents has, on the evidence available here, one named factory to show for it. That is not necessarily a red flag for a hardware startup seven years into a hard engineering problem — pilots take time — but it is a gap between marketing breadth and operating proof that a reader should hold onto.

The risks

• Single-site concentration: the only publicly confirmed commercial installation is the one Jharkhand steel plant (The Ken, 2023); if that relationship or that plant’s output changes, there is no second documented site to fall back on in the public record.
• Financial fragility in the one year disclosed: FY24 saw EBITDA fall by nearly 189 times and net profit fall by close to 13 times on a year-on-year basis, alongside a 29.8% drop in net worth (Tofler/MCA filing) — a profile consistent with a company still burning through pre-Series A capital rather than generating operating cash.
• Benchmark compression risk: Ossus’s central pitch is a cost advantage against conventional electrolysis, cited at $4-6/kg versus its own sub-$1/kg (NatNavi, IndianStartupNews, 2023); as electrolyser costs and renewable power tariffs continue to fall globally, that gap is not guaranteed to hold, and no source reviewed here shows Ossus publishing an updated benchmark since 2023.

The takeaway

The lesson in Ossus’s file is not really about hydrogen. It is about how long a genuinely novel piece of hardware can stay invisible to the outside world while it is being proven, and how much of a company’s story a reader has to reconstruct from funding gaps and filing dates rather than from the company’s own announcements. Ossus went five years between its first disclosed accelerator ticket and its next confirmed institutional dollar, and it still has just one named commercial site to show for nine years of work. That is not a verdict on whether the technology works — the pilot numbers suggest it does, at small scale — but it is a reminder that a compelling unit-economics slide and a functioning industrial site are two different kinds of proof, and only one of them is fully visible from the outside.

Frequently asked questions

What does Ossus Biorenewables actually make?

It makes and operates OB HydraCel, a bio-electrochemical reactor that uses microbes already present in industrial wastewater to generate green hydrogen on-site while treating the effluent, according to the company and Third Derivative’s portfolio description.

When was Ossus Biorenewables founded, and by whom?

It was incorporated on 16 October 2017 (MCA filing via Tofler) by Suruchi Rao (CEO), Shanta Rao (CLO) and Kamar Suhail Basha (CTO), per The Ken’s Green Margins newsletter.

How much funding has Ossus Biorenewables raised?

At least $2.4 million is confirmed, from a pre-Series A round led by Gruhas with Rainmatter Climate in April 2023, on top of an earlier undisclosed pre-seed from Shell E4 (2018) and an undisclosed iDEX grant (January 2023). Other trackers cite a higher lifetime total, but this piece could not verify that figure from a source it opened directly.

Where is Ossus Biorenewables actually operating?

The only publicly documented commercial deployment is a steel plant in Jharkhand, running since 2020 and processing about 6,000 litres of effluent a day to produce roughly 30 kg of hydrogen, per The Ken (July 2023).

Is Ossus Biorenewables profitable?

No. In FY24 (year ended 31 March 2024), the only year with disclosed financials, both EBITDA and net profit fell sharply year-on-year and net worth declined by 29.8%, according to an MCA filing reported by Tofler.

Sources

Figures are as of September 2026. Currency converted at $1 = Rs 96.0 as of 18 September 2026 (Trading Economics).

• The Ken, Green Margins newsletter, “The microbes minting green hydrogen from wastewater,” July 2023
• Inc42, Ossus Biorenewables company and funding profile, accessed September 2026
• Tofler, Ossus Biorenewables Private Limited company and financial filing summary (FY24, MCA data), accessed September 2026
• CB Insights, Ossus Biorenewables financials and funding profile, accessed September 2026
• Third Derivative, Ossus Biorenewables portfolio page, accessed September 2026
• Ossus Biorenewables company website (ossusbio.com), accessed September 2026
• Outlook Business Startup, “Ossus Biorenewables raises $2.4 million from Gruhas, Rainmatter Climate in pre-Series A round,” April 2023
• IndianStartupNews, “Green energy startup Ossus Biorenewables raises $2.4M led by Rainmatter, Gruhas,” April 2023
• IamRenew, “Green Energy Startup Ossus Raises Pre-Series A Round Worth $2.4 Mn,” April 2023
• NatNavi, “Ossus Biorenewables Secures $2.4 Million Funding,” 2023
• Rainmatter Grove forum, “Rainmatter Climate invests in Ossus Bio,” April 2023

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