There are 80 million kilometres of energy infrastructure on the planet. Power lines, gas pipelines, railways. Most of it is still inspected from the air the way it was in 1990: by helicopter.
HyLight, a Paris startup out of Y Combinator, is trying to retire that helicopter. Its HyLighter is a hydrogen-filled airship drone that flies 350 kilometres per mission, hovers at millimetre precision, and emits nothing in flight.
It has already flown for Enedis, Europe's largest power-line operator. SNCF, NaTran, Terega and Suez are named customers on its site.
A €3.7M seed round in April 2024 (backed by Y Combinator, Tesla co-founder Marc Tarpenning and Earth VC) funds the bet that storing hydrogen inside the balloon solves the weight problem that keeps fuel-cell aviation grounded.
The unit economics, 350 km per flight against helicopter operating costs, are what turn a niche French startup into a benchmark for the energy-inspection market.
TIMELINE: HyLight
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2022 ──── 2023 ──── 2024 ──── 2025 ──── 2026
🎈 🧪 💰 🔌 ◉ NOW
Founded YC €3.7M Enedis VivaTech
Paris S'23 seed Nord demo
round Pas-de-
Calais
Source: Y Combinator company profile; Earth VC announcement; H2Tech
First reference inspection contract with Europe's largest power-line operator, covering high-voltage lines in northern France with no greenhouse gas emissions during flight.
Why the helicopter is the incumbent to beat
Infrastructure operators fly three things today. Helicopters cover long ranges but burn fuel and cost thousands of euros per flight hour. Quadcopter drones are emission-free but short on range and payload. Fixed-wing drones and planes cover distance but cannot hover, so they miss the fine defects at the top of a pylon.
| Parameter | Helicopter | Quadcopter drone | HyLighter |
|---|---|---|---|
| Range per mission | high | ✗ short | ✔ 350 km |
| Hover capability | ✔ yes | ✔ yes | ✔ yes |
| Emissions in flight | ✗ jet fuel | ✔ zero | ✔ zero |
| Endurance | 3–5 h | ◐ 20–40 min | ✔ up to 10 h |
Nothing on that list combines all four columns. That gap is the whole market position.
Hydrogen, without the cylinder problem
Fuel cells have a weight problem in aviation. "For one kilo of hydrogen, you have 20 kilograms of cylinders," HyLight CEO Martin Bocken told Tech.eu at the 2024 raise. The standard answer, pressurised tanks, makes the payload math collapse before takeoff.
HyLight's solution is to delete the cylinder. The hydrogen is stored directly inside the envelope, acting as both lifting gas and fuel source. That single decision turns an airship into a long-endurance sensor platform: 10 hours aloft, 35 km/h cruise speed, LiDAR, thermal and infrared cameras running the whole way.
Millimetre-level data is the point. A slow, stable platform reads a corrosion spot on a pipeline or a vegetation risk on a line that a fast aircraft blurs past. Bocken's own framing for safety: the airships carry 90 percent less risk of damage or injury on impact than drones of similar payload, and follow the same regulations as regular drones.
The customer list suggests the pitch lands. Enedis for power lines, NaTran and Terega for gas networks, Suez for water, SNCF for rail.
The unit math
The market numbers are large enough to matter for a thesis. Energy infrastructure spans roughly 80 million kilometres globally. Methane leaks from oil and gas infrastructure account for about 4 percent of global greenhouse gas emissions, with an estimated $7 billion in annual losses in Europe and North America. Power outages cost the United States about $18 billion a year.
Those figures are why inspection frequency is climbing. Regulation is tightening, and operators are being pushed to find faults in vast areas, the needle-in-a-haystack problem HyLight's founders describe. Per-kilometre inspection cost is the lever that decides whether an operator flies once a year or every quarter.
HyLight's economics are simple: a vehicle with near-zero fuel cost, low maintenance, and no crew in the air. The comparison against a multi-hundred-thousand-euro helicopter hour is favourable enough that the company has produced seven iterations and logged more than 150 hours of flight time since its 2022 founding.
The turning point
As we wrote in August, quadruped robots are already walking substation floors for the same reason: grid assets are too cheap to inspect by helicopter and too critical to skip. HyLight attacks the same problem from the air, at longer range.
2026 is when the story moves from pilots to fleet. The company demonstrated its autonomous airship at VivaTech in June, and was named to Google's Energy AI accelerator cohort in late August. Twenty HyLighters are manufactured and deploying across Europe. The seed round from April 2024 was its last disclosed raise. The interesting question for the next 12 months is who writes the Series A.
The scar on the thesis is the usual one for French deeptech: certification timelines and go-to-market against incumbents who own the utility relationships. Hydrogen airships also carry a public-relations history they did not create. The engineering is sound; the sales cycle is long.
None of that changes the core arithmetic. When an inspection tool is ten times cheaper per kilometre, at equal precision, and zero-emission, it does not need the market to change its mind. It needs one procurement cycle.
The Series A: size, lead, and whether it funds international (non-France) deployments
Enedis contract expansion beyond Nord Pas-de-Calais
Whether NaTran or Suez move from named customer to multi-region contract
Certification status with French authorities and the European Union Aviation Safety Agency (EASA)
Unit count: the gap between the 20 deployed HyLighters and a stated fleet target
Why the airship thesis has a buyer now
The airship renaissance is already visible at the edges: Flying Whales for cargo, Airlander 10 for passenger transport. HyLight is the version of that thesis with a buyer's budget behind it, not a novelty fund. Utilities pay for prevention, and prevention is exactly what a slow, precise, cheap airship sells.
The infrastructure-inspection stack is consolidating around autonomy. If HyLight closes its next round and expands Enedis-style contracts across Europe, hydrogen airships stop being a curiosity and become a line item in grid maintenance budgets.