London continues to be Europe's climate tech stronghold.
Climate tech startups based in the British capital attracted more investment than any other European city last year, according to an Impact Loop analysis of over four thousand of venture capital deals.
The findings are no shocker given that London is also Europe's strongest tech ecosystem overall.
However, what's perhaps more surprising is that venture capital investment for climate tech in London actually grew last year to $2.1bn, from $1.8bn in 2024, bucking a wider downturn in funding for green technologies.
In contrast, other major hubs such as Paris, Stockholm, and Berlin all saw climate tech investment retreat sharply in 2025. (Here is the full breakdown across 20 cities).
The numbers are driven in part by two large rounds. In December, Kraken – the energy software platform spun out of Octopus Energy – raised $1bn. Octopus Energy itself secured $320m in the same month.
Earlier in 2025, EV charging company Connected Kerb pulled in $86m, while consumer energy startup Fuse Energy raised $70m. Meanwhile, electric parcel delivery startup Hived raised $42m, and direct air capture company Mission Zero Technologies raised $29m.
London-based climate tech investors participated in many of these rounds. Those include Octopus Ventures, Clean Growth Fund, Molten Ventures, Sustainable Ventures, Counteract, 2150, Eka Ventures, and Bethnal Green Ventures.
Larger funds with strong climate portfolios – including Lightrock, Atomico, and Giant Ventures – also feature prominently.
'Supportive ecosystem'
The UK continues to create commercial pull for companies working on grid flexibility, EV infrastructure, and industrial decarbonisation – three of London's strongest deal categories in 2025.
Ingrid Holmes, deputy CEO of the Green Finance Institute (GFI), says the city's infrastructure partly explains the momentum.
"We have a very supportive startup ecosystem here – Innovate UK grant funding, the catapult programmes, quite active public banks," she tells Impact Loop. "There's a really deliberate and intentioned approach in the UK."
However, while the startup ecosystem is growing, Holmes points to the need for more support and capital at the Series B stage and beyond, especially for hardware-heavy technologies.
"We need to support these companies on their commercialisation journey," she says.
The findings come as climate investors, founders and ecosystem players gather in the city for London Climate Action Week (LCAW).
This year, the event, which is one of the world's largest gatherings for the climate, has coincided with record-breaking heat across the UK and much of Europe.
Pictured: Angel Issa (Octopus Ventures); Beverley Gower Jones (Clean Growth Fund); Ingrid Holmes (GFI); Melanie Hayes (Bethnal Green Ventures); Jacob Bro (2150); Pal Erik Sjatil (Lightrock); Cameron Mcclain (Giant Ventures); Murvah Iqbal (HIVED); Hayden Wood (Beams); Karl Bach (Axle Energy); Shiladitya Ghosh (Mission Zero) Chris Pateman-Jones (Connected Kerb)