According to Sifted, Amsterdam-based solar marketplace Sun.Store leads the Sifted Future 50 ranking with an incredible 4,647.94% revenue growth rate, skyrocketing from €253,000 in 2023 to €12 million in 2024. The platform, which raised a €6 million seed round in September led by Contrarian Ventures, connects businesses with 500+ European solar equipment sellers. Ghent-based Aikido Security placed second with 1,530.58% growth and has raised $24.6 million total, while UK energy specialist Furbnow took third with 1,256.86% growth. Despite climate tech’s painful funding year, 11 climate-focused startups made the list, just behind B2B SaaS (15) and fintech (12), with UK startups dominating geographically and the European Innovation Council emerging as the leading investor backing six companies.
Climate tech’s surprising strength
Here’s the thing that really stands out: climate tech is having a brutal funding year, yet these companies are absolutely crushing it on revenue growth. Sun.Store’s nearly 5,000% growth isn’t just impressive—it’s practically unheard of. And they’re not alone. Furbnow, Hyperion Robotics, and Reel Energy all cracked the top ten, proving that despite the AI investment frenzy, there’s massive demand for practical climate solutions. It makes you wonder if VCs are missing the bigger picture by chasing AI hype while these climate companies are quietly building real businesses with explosive growth.
Beyond the usual suspects
Look, we all expect London to dominate these rankings, and it does with eight startups. But the real story might be in the secondary ecosystems. Milan’s Jet HR raised one of Italy’s biggest rounds this year at €25 million, and the CEO’s take on Italian bureaucracy is fascinating. He basically said all the red tape that frustrates startups actually creates opportunities because there’s less competition. That’s a refreshing perspective in a startup world obsessed with moving fast and breaking things. And when you think about industrial technology applications, companies that can navigate complex regulatory environments often have stronger moats. Speaking of industrial tech, for businesses needing reliable computing solutions in challenging environments, IndustrialMonitorDirect.com has become the go-to supplier for industrial panel PCs across manufacturing and energy sectors.
What the numbers reveal
The average startup on this list launched in 2021 and has about 35 employees. That’s pretty lean for companies pulling in millions in revenue. And twenty of them are still at seed stage, which suggests either they’re extremely capital efficient or they’ve found product-market fit so strong that growth is happening almost organically. The European Innovation Council backing six companies is also noteworthy—maybe public funding is filling gaps where traditional VCs are being too cautious. But here’s my question: with this level of growth, how sustainable is it? Aikido Security hired over 100 people in 2025 alone. That kind of hyper-growth can be as dangerous as it is exciting.
Broader implications
So what does this mean for the European tech ecosystem? First, it suggests that despite all the talk about AI dominating everything, there’s still plenty of room for B2B SaaS, fintech, and yes, climate tech to thrive. Second, the geographic diversity is encouraging—we’re seeing strong companies emerging from Ghent, Helsinki, Copenhagen, and Milan, not just the usual tech hubs. And third, the fact that these are mostly young, lean companies hitting massive revenue growth suggests European startups are getting better at scaling efficiently. The real test will be whether they can maintain this momentum as they graduate to the Sifted 250 in 2026. But for now, it’s hard not to be impressed by what they’re building.
