11 climate tech soonicorns – ranked by growth signals

Europe already has a healthy herd of climate tech unicorns. They include the likes of Stegra, Vinted, 1KOMMA5°, and – the latest addition – Fuse Energy.

Despite a slowed VC funding environment, many climate tech startups are still raising big rounds at hefty valuations – or growing their revenues – and are on track to enter the unicorn club sometime in the near future. These risers are what some would call “soonicorns.”

While definitions vary, we categorise a soonicorn as any company that has a valuation of over $500m and has closed at least one new funding round since 2020.

This list is based on Dealroom data and our own investor database. It is ranked by growth signals that combine data such as funding velocity, employee growth, and market traction.

Let's begin.

1. Proxima Fusion

Headquarters: Munich, Germany.

Valuation: $715m.

Prominent investors: Cherry Ventures, Balderton Capital, UVC Partners, DeepTech & Climate Fonds, Plural, Lightspeed, Bayern Kapital.

Munich-based fusion energy startup Proxima Fusion designs optimised stellarator reactors – a next-generation fusion technology aimed at producing stable, continuous clean power. Spun out of the Max Planck Institute for Plasma Physics in 2023, it combines physics, engineering, and AI to accelerate reactor design. In June 2025 it secured €130m in Series A financing, followed by a €15m extension, making it one of Europe’s best-capitalised fusion startups.

2. CuspAI

Headquarters: Cambridge, United Kingdom.

Valuation: $520m.

Prominent investors: NEA (New Enterprise Associates), Temasek, Samsung Ventures, Hyundai Motor Group, Northzone, Giant Ventures

CuspAI builds a generative-AI platform to design new materials for sustainability and clean energy, using deep learning and molecular simulation. Founded by Prof. Max Welling and Dr. Chad Edwards, it acts like a “search engine for materials,” enabling rapid discovery of novel structures. In 2025, it raised $100m in a Series A, co-led by NEA and Temasek.

3. INERATEC

Headquarters: Karlsruhe, Germany.

Valuation: $519–779m.

Prominent investors: Piva Capital, HG Ventures, TDK Ventures, Copec Wind Ventures, RockCreek, Emerald, Samsung Ventures, Engie New Ventures, Safran Corporate Ventures, Planet A.

INERATEC produces e-kerosene and synthetic fuels by combining green hydrogen with captured CO2. Its modular power-to-liquid plants aim to decarbonise aviation and other hard-to-electrify sectors. Backed by a $129m Series B, INERATEC is currently working on its first large plant in Frankfurt.

4. Marvel Fusion

Headquarters: Munich, Germany.

Valuation: $497–746m

Prominent investors: EQT Ventures, Siemens Energy Ventures, European Innovation Council (EIC) Fund, Earlybird, Bayern Kapital, Tengelmann Ventures.

Marvel Fusion develops laser-based fusion energy using short-pulsed lasers and nanostructured targets to compress fuel and spark fusion reactions. Founded in 2019, it’s currently building a laser facility in partnership with Colorado State University in the US. In 2025, it raised €113m in Series B, including new backing from EQT Ventures, Siemens Energy, and the EIC Fund.

5. Kaluza

Headquarters: London, United Kingdom.

Valuation: $500m.

Investors: Ovo Energy, AGL Energy.

Kaluza offers EV charging, billing, and grid optimisation using AI and predictive software. It was born as a spin-out from Ovo Energy in 2019. Ovo is reportedly exploring selling its 80% stake in Kaluza at a valuation north of $1 billion – so it could become a unicorn quite soon if that deal goes ahead.

6. WAAT

Headquarters: Malakoff, France.

Valuation: $440–660m.

Prominent investors: Bpifrance, RAISE, DWS Group.

WAAT deploys and operates a network of fast-charging EV stations across France, combining both hardware and software. Since its founding in 2018, it has raised €130m in growth funding to accelerate its infrastructure rollout nationwide. The company has posted a positive EBITDA for three consecutive years, with annual revenues most recently reaching €70m.

7. Empact

Headquarters: Cologne, Germany.

Valuation: $440–660m.

Prominent investors: Bauwens Digital, Hopp Family Office, Sustainable Development Capital.

Empact helps real estate owners decarbonise their buildings through energy-efficiency retrofits and smart systems. Founded in 2021, it integrates hardware and analytics to cut emissions in the built environment. It raised €100m in late-stage funding in October 2025 to scale across European properties.

8. Qvantum

Headquarters: Malmö, Sweden.

Valuation: $409–614 m.

Prominent investors: Gullspang Invest, DIG Investment, SEB Greentech, IMAS Foundation.

Qvantum produces next-generation heat pumps and thermal management systems, enabling efficient heating and cooling in cities. Originally founded in 1993, it has pivoted strongly into climate tech in recent years. It raised €93m in a Series C round in January 2025 to increase production and commercial reach.

9. Syre

Headquarters: Stockholm, Sweden.

Valuation: $400–600m.

Prominent investors: TPG, Vargus Holding, H&M, Norrsken VC.

A joint venture between H&M and Vargus (the investment vehicle behind Northvolt, Stegra, Aira etc.), Syre develops textile recycling technology that turns fashion waste into reusable feedstock. Founded in 2023, it has raised $100m as it looks to scale its textile recycling plants.

10. Deepki

Headquarters: Paris, France.

Valuation: $660–990m.

Prominent investors: Axeleo Capital, Bpifrance, Statkraft Ventures.

Deepki provides ESG software for real estate portfolios, offering analytics and insights for decarbonisation and regulatory compliance. Founded in 2014, it has managed to compete in a crowded green accounting space, partly by acquiring two rivals: Fabriq in 2022 and Nooco in 2023. The company’s latest funding round was a €150m Series C back in 2022. It reached revenues of $30m in 2024.

12. Connected Kerb

Headquarters: London, United Kingdom.

Valuation: $726m.

Prominent investors: Technation, Aviva Investors, National Wealth Fund.

Connected Kerb builds and operates smart EV charging infrastructure at the curb, combining hardware and software to serve cities and fleets. Since 2017, it has raised $231m to scale its charging network across the UK.

Pictured top: CuspAI founders; Proxima Fusion Franscesco; Marvel Fusion Heide; Empact Sebastian; kaluza CEO; Syre CEO; Vincent Bryant (Deepki)