London is Europe's top destination for cleantech VC. These 11 active investors are writing checks for UK climate and energy transition startups in 2026.
London has 70% of all UK cleantech VC investment flowing through it. The sector pulled in $3.5B in 2023, and deal volume has held up in 2026.
The money in 2026 is moving toward grid technology, industrial decarbonization, and clean energy infrastructure. Pure software climate plays without hardware traction close less often.
What gets funded: startups with real emissions reduction data, clear commercialization paths, and regulatory readiness. Concept-stage decks without pilots rarely close in this market.
Set up an Ellty data room with your technical documentation, emissions impact model, and pilot results before reaching out. London cleantech VCs ask for these before second calls.
| Type | Check size | Sector focus | Website | |
|---|---|---|---|---|
| Clean Growth Fund | Seed to Series A | £500K-£5M | Energy, transport, agrifood, buildings | cleangrowthfund.com |
| Kiko Ventures | Seed to Series C | £5M-£50M+ | Energy tech, environment tech, climate infra | kiko.vc |
| TSP Ventures | Pre-seed to Seed Extension | £500K-£2.5M | Climate, cleantech, materials, energy | tspventures.co.uk |
| Lowercarbon Capital | Seed to growth | $5M-$50M+ | Carbon removal, clean energy, electrification | lowercarbon.com |
| Octopus Ventures | Seed to Series B | £1M-£10M+ | Clean energy, renewable infra, climate tech | octopusventures.com |
| Sustainable Ventures | Pre-seed to Seed | £100K-£2M | Circular economy, cleantech, sustainability | sustainableventures.co.uk |
| Balderton Capital | Series A to growth | $5M-$50M+ | Clean energy, deep tech, climate infra | balderton.com |
| Future Planet Capital | Seed to Series B | £500K-£5M+ | Climate tech, deeptech, blue economy | futureplanetcapital.com |
| Parkwalk Advisors | Seed to growth | £500K-£5M+ | Cleantech, deeptech, materials, energy | parkwalk.vc |
| Breakthrough Energy Ventures | Series A to growth | $5M-$100M+ | Clean energy, industrial decarbonization, fusion | breakthroughenergy.org |
| Just Climate | Growth stage | $50M-$200M+ | Climate solutions, energy transition, decarbonization | justclimate.com |
See which cleantech VCs open your pitch
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Start free 14-day trialWhat is a London cleantech investor?
A London cleantech investor backs companies reducing greenhouse gas emissions or improving energy and resource efficiency. They range from early-stage funds like Clean Growth Fund to growth-stage platforms like Just Climate.
Specialists read pilot results and emissions impact models before looking at team slides. They want to see a technology working at small scale before committing capital to commercial rollout.
Check sizes run from £100K at Sustainable Ventures to $200M+ at Just Climate. Most seed-stage cleantech rounds in London land between £500K and £5M.
London's cleantech output includes Highview Power, Mixergy, and Drift Energy. Compare London AI investors and London healthtech investors to understand how technical diligence differs across deep-tech sectors.
The cleantech companies raising in 2026 have working pilots, measurable emissions reductions, and a team that understands the regulatory path to scale.
11 London cleantech investors
1. Clean Growth Fund
Clean Growth Fund is a £101M climate VC fund investing in UK startups that reduce emissions or improve resource efficiency. They led a £4.5M round into Clean Food Group in April 2026 and invested in Oriole Networks in early 2026.
- Recent Deals: Clean Food Group £4.5M lead (Apr 2026); Oriole Networks investment (2026); Clean Growth Fund II £56.8M initial close (Aug 2025); 19 Fund I portfolio companies
- LinkedIn: Clean Growth Fund LinkedIn
- Sector Focus: Energy, transport, industrial decarbonization, buildings, agrifood, circular economy
- Stage Focus: Seed to Series A
- Location: London, UK
- Website: cleangrowthfund.com
2. Kiko Ventures
Kiko Ventures is the cleantech arm of IP Group with a £375M evergreen fund. They backed Mixergy's Series C in March 2025 and Mantle8's Seed in February 2025, with 14 portfolio companies as of late 2025.
- Recent Deals: Mixergy Series C (Mar 2025); Mantle8 Seed (Feb 2025); OXCCU follow-on (2025); 14 portfolio companies; £375M evergreen platform
- LinkedIn: Kiko Ventures LinkedIn
- Sector Focus: Energy tech, environment tech, climate infrastructure, high tech
- Stage Focus: Seed to Series C
- Location: London, UK
- Website: kiko.vc
3. TSP Ventures
TSP Ventures backs early-stage hard science and engineering startups tackling climate change. They co-led Nanomox's £2.4M seed in February 2026 and led Reaforma's £1.1M pre-seed for carbon-negative cement in January 2026.
- Recent Deals: Nanomox £2.4M co-lead (Feb 2026); Reaforma £1.1M lead (Jan 2026); PES Technologies (May 2025); Pathfinder EIS Fund launching Apr 2026
- LinkedIn: TSP Ventures LinkedIn
- Sector Focus: Climate, cleantech, materials, energy, water, carbon removal
- Stage Focus: Pre-seed to Seed Extension
- Location: London, UK
- Website: tspventures.co.uk
4. Lowercarbon Capital
Lowercarbon Capital backs founders cutting carbon across clean energy, electrification, and industrial decarbonization. They led Fuse Energy's $70M round in December 2025, bringing the London energy startup to a $5B valuation.
- Recent Deals: Fuse Energy $70M lead at $5B valuation (Dec 2025); Commonwealth Fusion Systems $863M round (Aug 2025); Emerald investment (2026); 200+ portfolio companies
- LinkedIn: Lowercarbon Capital LinkedIn
- Sector Focus: Carbon removal, clean energy, electrification, industrial decarbonization, sustainable agriculture
- Stage Focus: Seed to growth
- Location: London and San Francisco
- Website: lowercarbon.com
5. Octopus Ventures
Octopus Ventures is the VC arm of the Octopus Group, writing £1M-£10M+ checks into seed to Series B companies. They backed Drift Energy's £4.65M seed for hydrogen-producing sailing vessels in 2025.
- Recent Deals: Drift Energy £4.65M seed (2025); Octopus Energy Generation $1B California cleantech investment (Feb 2026); 18 investments in 2025; energy and climate portfolio active
- LinkedIn: Octopus Ventures LinkedIn
- Sector Focus: Clean energy, renewable infrastructure, climate tech, deep tech
- Stage Focus: Seed to Series B
- Location: London, UK
- Website: octopusventures.com
Share your cleantech deck with trackable links
Use Ellty to track which London investors open your data room.
Start free 14-day trial6. Sustainable Ventures
Sustainable Ventures has built Europe's largest climate tech startup ecosystem. They have supported 500+ startups with £1B of investment raised across their portfolio, and run the Better Futures+ program for underrepresented climate founders.
- Recent Deals: 500+ portfolio companies; £1B raised across ecosystem; Better Futures+ cohorts active in 2025-2026; GLA-funded programs ongoing
- LinkedIn: Sustainable Ventures LinkedIn
- Sector Focus: Circular economy, cleantech, sustainability, resource efficiency
- Stage Focus: Pre-seed to Seed
- Location: London, UK
- Website: sustainableventures.co.uk
7. Balderton Capital
Balderton Capital is a European multi-stage VC with a London headquarters and a clean energy track record. They co-led Fuse Energy's $70M round alongside Lowercarbon in December 2025, and made 22 investments in 2025.
- Recent Deals: Fuse Energy $70M co-lead with Lowercarbon (Dec 2025); 22 investments in 2025; 14 investments in early 2026; European tech and clean energy mandate
- LinkedIn: Balderton Capital LinkedIn
- Sector Focus: Clean energy, deep tech, fintech, enterprise software
- Stage Focus: Series A to growth
- Location: London, UK
- Website: balderton.com
8. Future Planet Capital
Future Planet Capital backs university spinouts and impact ventures in climate tech, deeptech, and blue economy. They invest globally from their London platform with a track record in nuclear fusion, agtech, and semiconductors.
- Recent Deals: Nuclear fusion, agtech, and semiconductor portfolio companies; Birmingham regional innovation team active; UK-wide spinout mandate; SDG-aligned portfolio
- LinkedIn: Future Planet Capital LinkedIn
- Sector Focus: Climate tech, deeptech, blue economy, life sciences, agtech
- Stage Focus: Seed to Series B
- Location: London and Birmingham, UK
- Website: futureplanetcapital.com
9. Parkwalk Advisors
Parkwalk Advisors invests in UK university spinouts across cleantech, deeptech, and materials with £450M under management. Their latest investment was in Quantum Motion in May 2026, and they backed xWatts in February 2026.
- Recent Deals: Quantum Motion Seed (May 2026); xWatts Seed (Feb 2026); 248 total investments; 8 IPOs; £450M AUM across cleantech and deeptech
- LinkedIn: Parkwalk Advisors LinkedIn
- Sector Focus: Cleantech, deeptech, materials, energy, quantum computing, MedTech
- Stage Focus: Seed to growth
- Location: London, UK
- Website: parkwalk.vc
10. Breakthrough Energy Ventures
Breakthrough Energy Ventures co-founded Cleantech for UK alongside Clean Growth Fund and Kiko Ventures. They have raised $2B+ in committed capital backing 90+ companies in grid, fusion, cement, and carbon removal.
- Recent Deals: 90+ portfolio companies globally; Cleantech for UK coalition co-founder; active deployment in grid and industrial decarbonization; Catalyst programme running 2025-2026
- LinkedIn: Breakthrough Energy LinkedIn
- Sector Focus: Clean energy, industrial decarbonization, grid, fusion, carbon capture
- Stage Focus: Series A to growth
- Location: London and Seattle
- Website: breakthroughenergy.org
11. Just Climate
Just Climate is Al Gore's growth-stage climate fund focused on large-ticket investments in commercially viable emissions-reduction technologies. They back clean energy and industrial decarbonization at institutional scale.
- Recent Deals: Growth-stage climate portfolio; large-ticket energy transition investments; clean energy and industrial decarbonization focus; active in UK market 2025-2026
- LinkedIn: Just Climate LinkedIn
- Sector Focus: Climate solutions, energy transition, industrial decarbonization
- Stage Focus: Growth stage
- Location: London, UK
- Website: justclimate.com
How to find active London cleantech VCs
Check each fund's last investment date on Crunchbase before reaching out. A cleantech fund that hasn't deployed in nine months may be between vintages or reassessing thesis.
Ask which partner leads your specific sector - not just climate broadly. A fund with energy partners may pass on circular economy deals, even if both sit under cleantech.
Read the due diligence process and virtual data room examples. Have your pilot results, emissions model, and IP ownership docs in an Ellty data room before any intro call.
What London cleantech investors read before your pitch
London cleantech VCs want pilot data before almost anything else. A working prototype with real emissions numbers gets a second meeting; a concept deck rarely does.
The second filter is the regulatory path. Startups with Ofgem approval, FCA readiness, or UKRI grant history close faster. Cleantech rounds without regulatory clarity drag on.
The third is the commercial model. Investors need to see a clear route to revenue - through energy contracts, product sales, or licensed IP. Use Ellty to share your commercial pipeline with trackable links before meetings.
How to verify a cleantech fund is deploying
Check if the fund's portfolio companies have raised follow-on rounds. A healthy portfolio with active companies signals the fund is still writing checks.
Ask for the partner's direct sector mandate. Clean Growth Fund partners split by vertical - energy, transport, buildings. Reaching the wrong partner wastes a month.
Dead portfolio companies without exits are a flag. A fund with multiple failures in 2022-2023 without pivots may be risk-averse in 2026. Check London proptech investors for comparison on how sector diligence differs.
How to pitch a London cleantech investor
Four steps for cleantech fundraising in London in 2026. Each step reflects how climate VCs screen deals.
- 1.Lead with pilot data, not the mission statementShow real emissions reduction numbers first. Investors gate on measurable impact before team slides.
- 2.Show your regulatory path is clearHave Ofgem, FCA, or UKRI documentation ready. Regulatory clarity closes cleantech rounds faster.
- 3.Map your commercialization timelineInvestors want a clear route to revenue. Model your first customer contracts before pitching.
- 4.Put everything in one trackable data roomUpload pilot results and IP docs to Ellty. Send trackable links so you know who reviews what.
How Ellty helps you land a London cleantech investor
You have the list. Now prepare your materials. Cleantech VCs ask for pilot data and impact models fast.
- 1.Upload emissions models and pilot reportsPut impact data and technical docs in one room. Investors check these before anything else.
- 2.Lock access to your IP and cap tableRequire email before investors view sensitive files. Use screenshot protection on legal documents.
- 3.Track which investors open your impact dataSee if VCs spend time on your pilot results or skip straight to financials. Follow up accordingly.
Common questions from London cleantech founders
- Most want real emissions reduction numbers from a working prototype. A concept with no pilot data is a fast pass.
- Not required, but it helps. Grants signal regulatory credibility and reduce due diligence time.
- Specialists like Clean Growth Fund and TSP Ventures if you are early-stage. Multi-sector VCs work for growth.
- Before first outreach. Put pilot results and your impact model in an Ellty room before emailing anyone.
- No pilot data and no regulatory clarity. Investors pass fast on concept-stage climate decks in 2026.
- Target six to eight funds that match your stage and sector. Track who opens your data room first.
