After years of strong growth, Europe’s climate tech sector is entering a more cautious phase. In 2023, startups raised over $20 billion — more than the US — marking a record high for the region. But by Q1 2025, funding has dropped to just $2.3 billion, the lowest level since 2020. The slowdown reflects a more mature market, growing investor interest in AI, and some startups shifting their focus toward defence and resilience. Still, this looks more like a healthy adjustment than a downturn — climate tech remains key to Europe’s energy security, industrial strategy, and geopolitical resilience.
To spotlight where innovation is still thriving, Vestbee asked two of the most active investors in European climate tech — CapitalT and Impact Ventures — to share which startups they’re watching closely. The only rule: no picking from their own portfolios.
Janneke Niessen, Founding Partner at CapitalT
- Material Exchange, Sweden
A digital platform transforming how fashion brands source sustainable materials by connecting them with responsible suppliers through AI-powered tools. By streamlining and digitizing the sourcing process, they reduce waste and emissions in one of the world's most polluting industries.
- Cemvision, Sweden
A Swedish startup revolutionizing cement production by recycled industrial waste and electrified kilns, achieving up to 95% lower CO₂ emissions compared to traditional methods. Their scalable, circular approach is already being adopted by major partners like Vatenfall.
- CEEZER, Germany
Reaching net zero is impossible without the use of high-quality CO₂ credits, CEEZER makes this path transparent, science-based, and actionable. The company has grown rapidly, recently expanding with a second office in the US, and its founder plays an active role in shaping carbon removal policy in Germany and the EU
- ctrl+s, Germany
After bootstrapping their way to product-market fit, they’ve now raised funding to scale their breakthrough solution that helps decarbonize complex supply chains, without spending months collecting data. Their approach makes emissions reductions faster, easier, and more actionable than ever.
- Cylib, Germany
A German startup enabling sustainable battery recycling through a proprietary process that recovers critical raw materials with minimal environmental impact. With strong backing from Porsche and Bosch, it's set to become a key player in Europe's circular battery economy.
- Terralayr, Switzerland
Terralayr is a Swiss startup transforming energy storage by offering “flexibility as a service” through a cloud-based platform that aggregates and virtualizes grid-scale battery assets. With over 5GW of development agreements and backing from major investors, it enables on-demand energy balancing
- Marvel Fusion, Germany
A German startup pioneering laser-driven inertial confinement fusion using ultra-short-pulse lasers and nanostructured hydrogen-boron fuel targets. With a demonstration facility underway in Colorado, it aims to deliver scalable, zero-carbon baseload energy
Gergely Iváncsics, Partner at Impact Ventures
- Sensoneo, Slovakia
Sensoneo develops a smart waste management solution leveraging IoT technology to optimize waste collection routes and schedules. Their sensors significantly reduce operational costs, traffic, and carbon emissions for cities and waste management companies across Europe.
- Heatventors, Hungary
Heatventors specializes in advanced thermal energy storage solutions, utilizing phase change materials to efficiently store and release heat or cold. Their technology offers a sustainable way to reduce energy consumption and improve the efficiency of heating and cooling systems of data centers, and is expanding to various applications.
- Hepta Insight, Estonia
Hepta Insight aces grid inspection with drones and AI-enhanced analysis. Anomaly detection and repair optimization maximizes efficiency and minimizes downtime. Their platform is helping energy providers worldwide make data-driven decisions.
- Wenerate, Hungary
Wenerate tracks energy consumption data and integrates the control systems of industrial technologies to optimize energy management on a common platform. Less cost & admin through automatic and visualized operation. Their client pool and growth rate suggests they are on a steady growth track.
- ReCatalyst, Slovenia
ReCatalyst is pioneering catalytic technologies for hydrogen technologies. The bottle-neck of electrolyzer and fuel cell production is the high demand for costly rare materials such as platinum the use of which ReCatalyst optimizes to enable a hydrogen revolution and decarbonization.
