Top 100 Cleantech Companies in the UK | 2026

UK cleantech companies raised £2.95b across 535 deals in 2025 — the sector’s second-strongest year on record, behind only the 2023 peak of £3.44b across 619 deals. The first quarter of 2026 has already delivered £571m across 173 deals, putting the sector on pace for another year above £2b. Across all time, UK cleantech companies have raised £18.7b in equity funding tracked by Beauhurst, with 76% of that total arriving since the start of 2020.

We’ve ranked the top 100 cleantech companies by total equity raised (all data sourced from the Beauhurst platform).

An overview of the cleantech sector

Cleantech covers companies building technology and services that reduce environmental impact, including renewable energy generation, energy storage, electric vehicle infrastructure, hydrogen production, carbon capture and removal, sustainable materials and packaging, circular-economy and recycling technologies, sustainable mobility, climate data and analytics, and energy-efficient computing.

Beauhurst tracks 12,218 active cleantech companies in the UK, up from 4,957 in the final quarter of 2015 — a 147% increase over the decade. Together, these companies generated £620b in turnover according to latest financials and support an estimated 583,373 employees across the UK.

Across all time, cleantech companies have raised £18.7b in equity funding tracked on the platform, making this the largest sector we’ve covered by total capital deployed. The 2023 peak of £3.44b has been followed by two further years above £2.3b, with 2026 already on a comparable trajectory.

Key findings

• Centrica tops the ranking with £1.13b raised. The South East-based energy utility — which generates, stores, and supplies energy including renewables — accounts for 6.0% of all UK cleantech equity raised to date and 11% of the top 100 alone.
• GRIDSERVE (£623m, South West) in solar storage and EV charging takes second, followed by ITM Power (£521m, Yorkshire and The Humber) in hydrogen, Highview Power (£507m, London) in long-duration energy storage, and OVO Group (£459m, South West). The top five account for 17% of all UK cleantech equity — the most dispersed top-five distribution in the series.
• London hosts 36 of the top 100, followed by the South East (21), East of England (13), and South West (eight). The top 100 spans 14 UK regions including all four nations, with Scotland represented by Aberdeen, Tayside, Highlands and Islands, and the East and West of Scotland. The East of England’s 13 entries reflect a strong Cambridge deep-tech cluster spanning batteries, materials, and AI for climate.
• Growth-stage businesses dominate the top 100 with 52 entries, followed by established (23), venture-stage (19), exited (four), and seed (two). The 27 mature names sit alongside 71 still-scaling growth and venture businesses — the highest growth-stage concentration we’ve seen in any sector, reflecting the capital-intensive nature of cleantech and the steady flow of late-stage rounds underwriting infrastructure-scale deployment.

Top 100 cleantech companies in the UK

The future of cleantech in the UK

UK cleantech company formations peaked in 2022 at 1,101 new businesses, then fell sharply to 487 in 2025 — yet annual investment has remained at unprecedented levels, with 2023 (£3.44b), 2024 (£2.39b), and 2025 (£2.95b) all clearing the £2.3b mark and 2026 already at £571m through the first quarter. The pattern is one we’ve now seen repeatedly in our sector series — formations cooling while capital concentrates on a more credible cohort of scaling businesses. In cleantech the gap is unusually stark, reflecting both the capital intensity of deploying energy infrastructure and the sheer breadth of demand pulling investment in.

The structural drivers behind that demand are unlikely to weaken. The UK’s legally binding net-zero-by-2050 target, accelerating EV adoption, AI-driven datacentre power demand, and the continued cost decline in solar, batteries, and electrolysers all create durable pull-through for the technologies in this list. Established operators like Centrica (£1.13b) and OVO Group (£459m) are building out renewable generation and demand-side flexibility at scale, while growth-stage battery and storage businesses including Highview Power (£507m), Field (£303m), Fidra Energy (£445m), and Nyobolt (£134m) are commissioning the infrastructure that will absorb intermittent supply.

A younger cohort of AI-native entrants — CuspAI (£144m) for novel climate materials, BeZero Carbon (£85m) for carbon ratings, Modo Energy (£48m) for renewable analytics, and Oriole Networks (£28m) for low-energy AI compute — points to where the next wave of formations is likely to cluster as software margins meet hard-tech deployment.

With this in mind, it’s possible that — depending on broader economic conditions and the pace of policy support — cleantech enters its second decade as a more concentrated but vastly better-capitalised sector, where the slowdown in new incorporations is offset by larger rounds for fewer, more credible scale-ups. The capital is already there at unprecedented levels; whether the pipeline of new founders rebuilds, or whether the existing cohort consolidates the bulk of the opportunity, will define the next phase of the UK’s energy transition.