Startup Deep Dive : Tessol — betting thermal batteries can beat diesel in India’s cold chain

Tessol builds cold-storage boxes and truck bodies that need no diesel generator and no permanent power connection, running instead on blocks of phase-change material it calls thermal batteries. The company says one of its PLUGnCHILL vehicles saves around 1,000 litres of diesel a year (company-stated, Startup Energy Transition award profile). Yet 13 years after its 2013 founding, Tessol has raised a reported $3.27 million (₹31 crore, $1 ≈ ₹96.0 as of 18 September 2026, Trading Economics) in outside capital, and its own regulatory filings show revenue falling 42.5% year on year in the financial year ended March 2024 (Tofler, FY24 filing).

That gap between the pitch and the numbers is the real story here. Tessol is a genuine engineering outfit with an IIT-Harvard founder, a patented-sounding physics trick, and a hundred-plus customer list in one of India’s most wasteful supply chains. It is also a small, thinly capitalised private company that has told its own backers, in its own words, about years when the money nearly ran out. Both things are true at once, and this piece tries to hold them together rather than pick one.

Quick facts

What they do

Tessol sells and leases hardware that keeps food and medicine cold without running a diesel genset or staying plugged into the grid around the clock. Its core product line, branded PLUGnCHILL, packs phase-change material (PCM) — a substance engineered to freeze and melt at a chosen temperature — into panels and tanks that are charged with electricity for a few hours and then released slowly to hold a set temperature for a full working day. The company sells three broad categories of hardware: stationary cold rooms for warehouses and dairies, mobile units fitted into trucks and vans for mid-mile transport, and smaller last-mile packaging for the final leg to a shop or a doorstep (Ankur Capital portfolio page; tessol.in company profile). Its customers sit in dairy, ice-cream, meat, seafood, poultry, horticulture, pharma distribution and e-commerce grocery delivery, and the company says it has worked with more than 100 of them (tessol.in; Startup Energy Transition profile).

The origin

Rajat Gupta studied mechanical engineering at IIT Delhi, graduating in 2003, then spent four years at Bosch before leaving for an MBA at Harvard Business School, finishing in 2010 (CIIE.CO founder profile, reproduced on tessol.in). After Harvard he became chief operating officer at Promethean Power Systems, a Pune-based startup building off-grid milk-chilling units for Indian dairy farms that had no reliable electricity. That job put him inside the exact problem Tessol would later try to solve at larger scale: how to hold a cold temperature in places where power is expensive, intermittent or absent.

Gupta then joined Infuse Ventures, the cleantech-focused early-stage fund incubated at IIM Ahmedabad, as an entrepreneur-in-residence, working on what is described as India’s first dedicated cleantech accelerator programme. It was during that stint, in 2013, that he decided to build Tessol himself rather than keep advising other founders, with a stated goal of building a “farm to fork” cold chain for India using thermal batteries instead of diesel compressors (CIIE.CO founder profile; tessol.in). Niranjana Neelakantan joined as co-founder and took the chief operating officer role. Infuse Ventures itself became one of Tessol’s earliest institutional backers, alongside Ankur Capital.

The struggle years

Tessol’s own retelling of its history, published by its incubator CIIE.CO and mirrored on its own site, does not read like a straight line. Gupta has said the company went through stretches of team attrition, funding that dried up, and “issues on the product side” serious enough that he has described entrepreneurship at that point as something close to no longer being a choice: quitting was not an option once a team was depending on him (CIIE.CO founder profile, undated account, reproduced on tessol.in). Neither Tessol nor CIIE.CO attaches exact dates to that period in the public version of the story, which is itself notable for a company that is otherwise fairly open about its milestones.

The financial record supplies a second, dated setback. For the financial year ended 31 March 2024, Tessol’s own MCA filings show total revenue down 42.5% against the prior year, net worth down 31.9%, and borrowings up 364.3% — a year in which the company shrank sharply on top and took on materially more debt to stay funded (Tofler financial summary, FY24 filing). Tofler’s ratio analysis for the same year puts operating margin at -22.4% and net margin at -22.0%, which points to an operating loss rather than a rounding blip. Tessol has not publicly commented on that year’s numbers; they come from its own statutory filing, not company messaging.

The turning point

The clearest inflection point on the public record is the Series B round that closed in June 2022: ₹7.5 crore led by Mela Ventures, with participation from existing backers 1crowdAngels and 1Fund (TechGraph, June 2022; Mela Ventures press release, June 2022; tessol.in funding announcement). Coming directly after the period Gupta has described as one of drying-up funding and team attrition, the round reads as the moment the company stopped being a going-concern question and started being a growth question again. Gupta framed the money at the time as fuel for “geographical expansion, capacity building, team building, new products, and application development” (TechGraph, June 2022), and Tessol did subsequently move to launch in the UAE and explore the European market (Startup Energy Transition award profile). What the round did not do, on the evidence available, is fix the underlying financial trajectory: the sharp revenue and margin deterioration recorded in the FY24 filing came almost two years after this raise, which suggests the turnaround was partial and specific to survival and market entry rather than to the core India business’s profitability.

The money behind it

• Total raised: a reported $3.27 million (roughly ₹31 crore, $1 ≈ ₹96.0 as of 18 September 2026, Trading Economics) across six rounds since 2014, as tracked by Crunchbase and Tracxn — modest by Indian cleantech standards for a company operating since 2013.
• Seed round: closed 11 August 2014, amount undisclosed (Tracxn funding timeline).
• Series A: from Infuse Ventures and Ankur Capital, amount undisclosed; Tracxn’s funding table dates this round to around March 2020 (tessol.in Series A announcement; Tracxn).
• Follow-on equity round: from early-stage firm 1Crowd alongside existing investors Infuse Ventures and Ankur Capital, amount undisclosed (BW Disrupt headline, “Tessol Raises Follow-on Equity Funding”).
• Series B: ₹7.5 crore, closed June 2022, led by Mela Ventures with 1crowdAngels and 1Fund; Piramal Fund Management and Credentia Trustee also appear among the round’s approximately 32 participating investors (TechGraph; Mela Ventures; Tracxn).
• What each backer changed: Infuse Ventures and Ankur Capital supplied the earliest institutional capital and, in Gupta’s case with Infuse, a direct professional bridge from his time as entrepreneur-in-residence there; Mela Ventures’ Series B is the round Tessol itself credits with funding its post-2022 geographic push into the UAE (Startup Energy Transition profile; TechGraph).
• Valuation: not disclosed. Both Tracxn and PitchBook list a Series B valuation field for August 2022 but redact the figure, and no later round has been reported since — meaning Tessol’s current valuation is effectively unknown outside the company and its investors.

How it makes money

Tessol is a hardware business first. It designs and sells (or, per its own materials, leases) physical units — cold rooms, insulated van bodies with PCM panels, and smaller last-mile boxes — to logistics operators, retailers and food and pharma companies, rather than selling temperature-as-a-service on a pure subscription basis (Ankur Capital portfolio page; tessol.in product pages). Money comes in from that hardware sale or lease, plus, based on how the sector generally works, ongoing recharging and maintenance revenue where Tessol operates the units directly.

• Where the pitch creates margin: a PCM thermal battery has almost no moving parts compared with a diesel-powered transport refrigeration unit, so Tessol’s stated case to customers is lower maintenance cost and a payback period of around six months on the upfront hardware spend (Startup Energy Transition profile, company-stated figures).
• Where costs sit: manufacturing the PCM panels and enclosures, and — visible in the FY24 filing — a rising debt-service cost, with borrowings up 364.3% year on year against a shrinking revenue base (Tofler).
• What the company does not publish: Tessol has not disclosed a take rate, a per-unit price list, or a split between outright hardware sales and any recurring service revenue, so this piece does not attempt to size those separately.
• The part people get wrong: the “no diesel” pitch is often read as “no electricity,” which is not the claim. Tessol’s own materials say its units still need 5–6 hours of grid power a day to fully charge the thermal battery; the saving is against a diesel compressor running continuously, not against electricity altogether (Startup Energy Transition profile).

The numbers

Tessol is a small private company and does not publish an annual report; what follows is drawn from its statutory MCA filings as summarised by Tofler and Tracxn, the two most complete verifiable sources found for this piece. Multiple years of exact absolute revenue and profit figures are not publicly available without a paid company-data subscription, so the table below presents only the specific, sourced figures that could be independently confirmed rather than a fabricated multi-year series.

Read plainly: Tessol shrank and levered up in FY24, and the most recent figure available, an estimated FY25 revenue band from Tracxn, is a wide enough range that it cannot confirm whether the business had stabilised, recovered, or kept shrinking. Absolute rupee profit-and-loss figures for any year, and the FY25 margin picture, are not independently verifiable from public sources at the time of writing.

Where the money comes from

Tessol does not publish a revenue split by product line, sector or geography, so what follows is a description of its stated business lines and customer base rather than a quantified breakdown.

• Product lines (by Tessol’s own categorisation): stationary cold rooms; mid-mile mobility units fitted to trucks and vans; last-mile insulated packaging (Ankur Capital portfolio page).
• Customer sectors named by the company: dairy, ice-cream, meat, seafood, poultry and horticulture, plus pharma distribution and e-commerce grocery delivery (tessol.in; Startup Energy Transition profile).
• Customer count: “more than 100 customers” is the company’s own stated figure; no named marquee client list or per-client revenue contribution has been published.
• Geography: India is the core market; the company says it has launched in the UAE and was evaluating entry into the European Union as of its most recent public update (Startup Energy Transition profile). No revenue figures are attached to either market.
• The surprise: for a company whose pitch is aimed at logistics and e-commerce, its earliest and most sector-specific origin story is dairy — Gupta’s prior job at Promethean Power Systems was built around milk-chilling for farms with unreliable power, and that is the problem Tessol’s core PCM technology was first adapted to solve (CIIE.CO founder profile).

The risks

• Deteriorating unit economics funded by debt: in FY24, revenue fell 42.5% year on year while borrowings rose 364.3% and net margin was -22.0% (Tofler). A small hardware company financing a shrinking topline with rapidly rising debt has less room to absorb a bad year than a well-capitalised one, and no later audited figures are public to show whether this reversed.
• Thin, angel-heavy capital base: Tessol’s total disclosed outside funding since 2013 is a reported $3.27 million, and its shareholding is split mostly between VC funds and a large pool of roughly 58 angel investors rather than concentrated among a few large institutional backers (Tracxn shareholding and funding data). That structure can make it harder to raise a large, fast follow-on round if the business needs one, compared with a startup backed by two or three deep-pocketed funds.
• A fragmented, capital-intensive competitive field: India’s cold-chain market was valued at close to ₹2,162.56 billion (₹2,16,256 crore) in 2025 and is forecast to grow at a 12.7% compound annual rate to 2035 (Expert Market Research), but the same research lists Tessol alongside large, better-capitalised players such as Snowman Logistics, CEVA Logistics, Container Corporation of India’s Fresh and Healthy unit, and several regional cold-storage operators. A hardware-and-technology specialist competing against integrated logistics companies with their own fleets and warehousing risks being squeezed on price even as the category grows.

The takeaway

The lesson in Tessol’s record so far is not about phase-change material or diesel savings; it is about the gap between a technically sound product and a durable business around it. A founder can leave Bosch, Harvard and a promising dairy-tech startup, build a genuinely useful piece of hardware, sign more than a hundred customers, and still spend more than a decade raising only a few million dollars while posting a year of falling revenue and rising debt. None of that makes the underlying engineering wrong. It does mean that “the technology works” and “the company is financially healthy” are separate claims that need separate evidence, and for Tessol, as of the most recent public filings, only the first one is well supported.

Frequently asked questions

What does Tessol actually make?

Cold-storage hardware — stationary cold rooms, mobile units fitted into trucks and vans, and last-mile insulated packaging — built around phase-change material thermal batteries instead of diesel-powered refrigeration compressors (Ankur Capital portfolio page).

Who founded Tessol and when?

Rajat Gupta and Niranjana Neelakantan founded Tessol in 2013 in Mumbai; the company was incorporated on 7 February 2013 as Thermal Energy Service Solutions Private Limited (Zaubacorp/Tofler CIN record; CIIE.CO founder profile).

How much funding has Tessol raised, and at what valuation?

A reported $3.27 million (about ₹31 crore) across six rounds since 2014, most recently a ₹7.5 crore Series B in June 2022 led by Mela Ventures (Tracxn; TechGraph). No valuation has been publicly disclosed for any round.

Is Tessol profitable?

Not as of its most recent available statutory filing. For the year ended 31 March 2024, Tofler’s ratio analysis shows an operating margin of -22.4% and a net margin of -22.0%, alongside a 42.5% year-on-year fall in revenue.

Is Tessol a listed company?

No. Tessol is a private limited company and has not filed for or completed an IPO on any Indian or foreign exchange.

Sources

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

• Tracxn, Tessol company profile — funding rounds, employee count, revenue estimate, shareholding, September 2026
• Tracxn, Thermal Energy Service Solutions Private Limited legal-entity profile — capital structure, September 2026
• Tofler, Thermal Energy Service Solutions Private Limited financial summary — FY24 revenue, margin and borrowing changes, filing year ended March 2024
• Zaubacorp / Tofler CIN record U29220MH2013PTC240243 — incorporation date and directors
• TechGraph, “Mela Ventures leads Rs 7.5 Cr funding round for TESSOL,” June 2022
• Mela Ventures, “Leading Cold Chain Solution provider, TESSOL raises INR 7.5 Cr from Mela Ventures,” June 2022
• tessol.in, “Mela Ventures leads Rs 7.5 Cr funding round for TESSOL” (company announcement)
• tessol.in, “Of Unwavering Determination” (CIIE.CO founder profile, reproduced)
• BW Disrupt, “Tessol Raises Follow-on Equity Funding”
• Ankur Capital, Tessol portfolio page
• Startup Energy Transition, award profile of Tessol — technology specifications, UAE/EU expansion
• Expert Market Research, “Top 10 Cold Chain Companies in India,” market size and competitor list, 2026
• Crunchbase, Tessol organization profile (funding totals, via search index)

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