European climate tech had a strong 2023, bringing in a number of the year’s largest rounds. The biggest tickets all went to companies building infrastructure and hardware.
The companies with the fastest-growing teams follow that trend. They come from a range of industries, from heat pump manufacturing to gigafactories (large-scale battery manufacturing facilities), but they’re all hardware or infrastructure focused.
We’ve calculated the fastest-growing companies using the percentage change in headcount they’ve shown over 12 months, from June 2023 to June 2024. We used data from Dealroom and reached out to all companies on the list.
To avoid results being skewed by early-stage businesses making lots of hires while growing quickly, companies must have raised at least $50m and have at least 25 employees.
Aira
Swedish startup Aira, which provides heat pumps to consumers, saw its headcount grow the most across the last 12 months. The company was started by Vargas, the investment fund that seeded climate unicorns Northvolt and H2 Green Steel. Last month, Aira secured €200m in debt to expand its heat pump rollout.
HQ city: Stockholm, Sweden
Founded: 2022
Headcount growth over last 12 months: 892% to 1,200 employees
Cylib
German startup Cylib recycles lithium-ion batteries: an increasingly big opportunity as more batteries found in products like electric cars reach the end of their life, and the need for components ramps up. Cylib secured a €55m Series A in May this year, led by World Fund and Porsche Ventures.
HQ city: Aachen, Germany
Founded: 2022
Headcount growth over last 12 months: 251% to 68 employees
Ingrid Capacity
Also Stockholm-based, Ingrid Capacity has seen its headcount grow 173% over the last 12 months. The company, which is working on energy storage batteries, currently has 41 employees and is set to welcome eight more in the autumn. Ingrid raised $100m in April this year.
HQ city: Stockholm, Sweden
Founded: 2021
Headcount growth over last 12 months: 173% to 41 employees
Weev
Weev operates an EV charging network across Northern Ireland. It raised a £50m round from Octopus Investments in May 2023 — the country’s largest ever VC round, according to Dealroom data.
HQ city: Belfast, Northern Ireland
Founded: 2022
Headcount growth over last 12 months: 167% to 48 employees
Jimmy Energy
French startup Jimmy Energy is building nuclear micro-reactors. The heat generated by them will be less expensive than using fossil fuels, its cofounder Antoine Guyot told Sifted earlier this year.
HQ city: Paris, France
Founded: 2020
Headcount growth over last 12 months: 146% to 91 employees
Basquevolt
Basquevolt is building a gigafactory to produce solid state cells, a form of battery that uses a solid electrolyte rather than a liquid to conduct electricity. Proponents say the batteries are more power dense and lighter than more conventional lithium-ion cells.
HQ city: Vitoria-Gasteiz, Spain
Founded: 2021
Headcount growth over last 12 months: 142% to 87 employees
Newcleo
UK-based Newcleo is Europe’s best-funded nuclear startup. The company secured €487m in total, according to Companies House filings, and it’s currently targeting a €1bn round, €87m of which it closed earlier this year.
HQ city: London
Founded: 2021
Headcount growth over last 12 months: 130% to 535 employees
Stark Future
Spanish startup Stark Future is building electric motocross bikes, which the company says prove EV tech is superior to gas.
HQ city: Barcelona, Spain
Founded: 2020
Headcount growth over last 12 months: 123% to 161 employees
GeoPura
British startup GeoPura is working on using hydrogen to power a range of activities, from film and TV production to construction. It’s received funding from the UK Infrastructure Bank, Siemens, Swen Capital and Barclays.
HQ city: Newcastle, UK
Founded: 2019
Headcount growth over last 12 months: 110% growth to 101
Electra
French EV charging startup Electra raised a mammoth €304m Series B earlier this year, led by Dutch pension fund PGGM. It’s building a network of fast-charging stations for EVs.
HQ city: Paris
Founded: 2020
Headcount growth over last 12 months: 92% to 322 employees
