Cleantech Companies in the UK: 1,579 Active Firms (2026)
Cleantech companies in the UK develop lower-emission energy, resource-efficiency and environmental technologies for commercial markets.
Buying centres tend to sit in energy, estates, operations, sustainability and engineering teams rather than a central technology budget. Sales motions vary by product type: climate-data and monitoring vendors can sell into mid-market and enterprise accounts on recurring contracts, while hardware, waste, water and industrial-decarbonisation suppliers usually face procurement teams, site trials and project delivery. Buyers include utilities, manufacturers, infrastructure operators, property owners and public-sector bodies. Engagements therefore range from specialist advisory or monitoring work to equipment supply, maintenance and multi-site deployment.
Read more
1,579 cleantech companies are actively trading in the UK, making the cohort sizeable but still more specialised than broad software or professional-services markets. Reported headcount totals 10,088 people, with employment spread across engineering, installation, monitoring, compliance and commercial roles. The market’s shape is partly explained by the breadth of buying centres: utilities and infrastructure owners create project-led demand, while property, manufacturing and public-sector customers pull in energy-efficiency, resource-management and environmental-monitoring suppliers.
Regulatory exposure depends less on the cleantech label than on the activity being sold. Grid-connected assets, energy services and demand-side products meet market-entry and connection requirements; water, waste and air-quality propositions can bring permitting, reporting and site-compliance duties. Public-sector work adds procurement discipline, while carbon-reduction claims need auditable baselines and measurement methods. The result is a market where technical buyers and compliance teams often sit close together.
Demand appears more durable where products cut energy use, waste handling or compliance cost, rather than where the sale relies mainly on a buyer’s voluntary climate budget. Hardware-heavy suppliers tend to face longer qualification cycles and working-capital pressure, while software and monitoring models can expand through estates and infrastructure portfolios once accepted. Scale-up scarcity is likely to persist: many businesses will remain project-led, and consolidation may favour groups that can bundle installation, measurement and maintenance without losing technical credibility.
What’s in the file
One row per company, 50+ columns — everything below plus each company’s verified directors, from Companies House filings.
Company data
Verified directors — included
1,579
Active firms
2026
218
Above £5M
reported revenue
253
New incorporations
since 2022
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Key facts
About 13% of the trading cohort reports turnover above £5M (218 of 1,579 firms) — the rest sits below that revenue band.
16% of the cohort was incorporated since 2022 (253 firms), so a sizeable share is in its first few filing cycles.
Cleantech firms usually sell into commercial settings where energy use, waste reduction or environmental performance affects procurement decisions.
The segment spans lower-emission energy, resource-efficiency and environmental technologies, rather than a single product category.
Business models range from technology development to project-led environmental services, which can make like-for-like comparisons difficult.
Top UK Cleantech companies
Financial sub-scores
Computed from 4 filingsDevelops carbon capture technology for industrial point sources, including modular capture systems and chemical solvents. Designs, builds and operates equipment that captures CO2 emissions from heavy…
Serves B2B industrial companies in hard-to-abate sectors, especially operators of space-constrained heavy industrial sites seeking to meet net zero or emissions reduction targets.
Financial Health
StableStable · 0% CAGR over 3y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsDevelops carbon capture technology for industrial emissions. Uses metal‑organic framework adsorbents and vacuum swing processes to remove CO2 from flue gas, supplying modular capture units and pilot…
Serves industrial emitters and plant operators in hard-to-abate sectors seeking carbon capture retrofits, including lime, energy-from-waste and biomass facilities, alongside CCUS project developers…
Financial Health
StableStable · Hiring · 55% CAGR over 2y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsProvides consulting, development, financing and implementation of energy infrastructure upgrades, including energy efficiency and zero‑carbon generation projects. Delivers projects for public and…
Serves public and private sector organisations across the UK and Ireland, including councils, colleges and accommodation providers seeking to reduce energy use and progress toward net zero carbon…
Financial Health
StrongStrong · Hiring · 46% CAGR over 5y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDesigns, finances, installs and operates onsite renewable energy systems for commercial clients under energy‑as‑a‑service agreements, including solar photovoltaic, combined heat and power, biomass,…
Serves UK businesses and organisations with high energy usage, especially those spending over £500,000 per year on energy and seeking lower-cost, lower-carbon onsite heat and power arrangements.
Financial Health
StrongStrong · Growing, Hiring · 17% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDesigns, manufactures and supplies lithium‑ion battery energy storage systems and hybrid power generators for commercial and industrial use. Offers Hussh Pod BESS units for purchase, hire or lease to…
Serves UK commercial organisations needing temporary or purchased power systems, including construction, healthcare, data centres, TV and film, rail, utilities, telecoms, EV charging and tower crane…
Financial Health
StrongStrong · Growing, Hiring · 63% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDesigns and installs district heating and cooling networks, including energy centres, distribution pipework and energy substations. Provides turnkey engineering services covering design, construction…
Serves UK public-sector bodies, property developers, commercial landlords, residential scheme owners and institutions needing district energy networks and low-carbon heating or cooling infrastructure.
Financial Health
StrongStrong · Growing, Hiring · 77% CAGR over 5y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 2 filingsDevelops, builds and operates battery energy storage systems that balance electricity grids and support integration of renewable power. Provides energy storage infrastructure and tools to monitor…
Serves energy-sector organisations involved in renewable infrastructure, including grid operators, BESS investors, asset owners and other stakeholders in the UK battery storage market.
Financial Health
HealthyHealthy · Profitable, Hiring · 29% CAGR over 1y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsProvides retrofit and energy services for social housing, installing technologies such as solar panels and batteries, aggregating homes to purchase electricity and participate in flexibility markets,…
Serves UK social housing landlords and their residents, alongside institutional investors and funders focused on climate and social-impact opportunities in housing retrofit and energy efficiency.
Financial Health
StrongStrong · Hiring · 47% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDevelops hydrogen production technology aimed at zero‑emission energy applications. Designs and commercialises electrolysis systems for generating green hydrogen for industrial processes such as…
Serves industrial B2B customers in hard-to-decarbonise sectors, including whisky and drinks production, ammonia/fertiliser manufacturing, mining and natural resources companies seeking green hydrogen…
Financial Health
StrongStrong · Hiring · 50% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDevelops aerodynamic technologies and services to improve wind turbine blade performance, including upgrade packs, blade optimisation analysis, leading edge protection, noise suppression devices,…
Sells to B2B customers in the wind energy sector, including onshore and offshore wind farm owners, operators and turbine asset managers responsible for blade performance and energy production.
Financial Health
WeakWeak · -56% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDevelops and manages battery energy storage systems for commercial and industrial energy users. Provides feasibility assessments, project management, financing, construction, and operational…
Serves large commercial and industrial energy users, including logistics, distribution, cold storage, manufacturing, processing and multi-facility campus operators, targeting plant, facility, energy…
Financial Health
DistressedDistressed
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 4 filingsProvides smart building management technology that meters, monitors and controls energy, utilities and environmental systems. Offers cloud software, sensors and automation to track electricity, gas…
Serves UK organisations managing commercial buildings or estates, including retail, education, property, markets and facilities teams responsible for single sites or multi-site portfolios.
Financial Health
StrongStrong · Hiring · 9% CAGR over 3y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsOperates an aggregated demand‑response and electricity balancing portfolio, optimising flexible generation, storage and industrial load for participation in energy markets. Provides asset…
Sells to B2B and public sector customers with flexible energy assets, including battery storage investors, gas peaking plant operators, industrial and commercial businesses, utility companies, and…
Financial Health
StableStable · -53% CAGR over 5y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsProvides battery energy storage and solar integration solutions for commercial and utility-scale energy projects, including system sizing, engineering design, equipment supply, installation, and…
Sells to solar installers, EPC contractors, renewable energy developers and partners delivering small and large commercial, industrial and utility-scale energy projects for UK business clients.
Financial Health
DistressedDistressed · -86% CAGR over 2y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsDevelops and delivers renewable energy projects, specialising in large-scale solar parks and commercial solar PV systems. Provides development, design, planning, grid connections, financing,…
Serves UK landowners, landlords, commercial property owners, industrial sites, schools and investors involved in large-scale solar parks and commercial renewable energy projects.
Financial Health
StrongStrong · Hiring · 22% CAGR over 2y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDevelops and supplies hydrogen and fuel cell power systems for off‑grid and mobile applications. Provides fuel cell generators, hydrogen refuelling equipment, and on‑site hydrogen production systems,…
Serves businesses and public-sector infrastructure operators needing off-grid power or hydrogen refuelling, including rail, transport, CCTV/security, environmental monitoring, parking, marine,…
Financial Health
StrongStrong · Growing, Hiring · 37% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsDevelops AI-based energy management software for commercial buildings. Platform analyses meter, BMS and sensor data to monitor consumption, provide dashboards, alerts and optimisation actions,…
Serves businesses that own or operate commercial building portfolios, particularly CFOs, energy managers and facilities teams responsible for energy use, carbon targets and costs across metered, BMS…
Financial Health
StrongStrong · -4% CAGR over 2y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsDevelops and deploys marine renewable energy systems, including tidal turbines and floating solar arrays. Provides project development, engineering and marine services, and works on energy storage…
Serves businesses, utilities, investors and project partners in the renewable energy sector, particularly organisations developing or procuring tidal energy, floating solar, energy storage and smart…
Financial Health
DistressedDistressed · -90% CAGR over 2y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsEngineers hydrogen fuel systems for heavy‑duty vehicles and equipment, including dual‑fuel conversions for diesel engines, hydrogen combustion powertrains, fuel‑cell range extenders, and mobile…
Serves B2B operators of heavy-duty commercial fleets and specialist equipment, including HGV, construction, engineering, airport, port and short-sea maritime operations seeking fleet decarbonisation.
Financial Health
StrongStrong · Growing, Hiring · 15% CAGR over 2y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 2 filingsDevelops, finances and manages renewable energy infrastructure projects, including onshore wind, solar photovoltaic and battery energy storage systems. Provides project origination, development,…
Serves businesses, energy-sector partners and project stakeholders across the UK involved in renewable infrastructure, including onshore wind, solar, battery storage and energy-from-waste assets.
Financial Health
DistressedDistressed
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 4 filingsDesigns and installs renewable heating and cooling systems for commercial organisations, including air and ground source heat pumps, solar PV and solar thermal systems, and chillers. Also provides…
Serves businesses and organisations needing commercial renewable energy, heating and cooling systems, including sites with roofs, car parks or ground space for solar infrastructure.
Financial Health
StableStable · -13% CAGR over 3y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 4 filingsDevelops, builds, owns and operates renewable energy projects including solar farms and battery energy storage systems. Manages project development, planning, construction and operation of…
Targets UK landowners, renewable energy investors, utilities and independent power producers, with large-scale solar and battery schemes intended to serve local communities and households.
Financial Health
StableStable · Hiring · 114% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsDevelops, builds, and operates large-scale photovoltaic solar power plants and energy storage systems. Provides project development, engineering, construction support, and operational services for…
Serves UK landowners and energy-sector organisations involved in large-scale solar, wind-solar and battery storage projects, including partners and stakeholders in renewable electricity…
Financial Health
StableStable · Hiring · 200% CAGR over 2y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsDesigns and installs commercial renewable energy systems including rooftop, ground‑mounted and carport solar PV, battery storage and LED lighting. Provides feasibility studies, project development,…
Serves businesses and public-sector organisations, including manufacturing, leisure, commercial real estate, education providers, councils and retailers seeking to reduce energy costs and carbon…
Financial Health
StrongStrong · Growing, Hiring · 34% CAGR over 2y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsProvides engineering services for industrial waste heat recovery, assessing recoverable heat from manufacturing processes and designing systems such as high‑temperature heat pumps and Organic Rankine…
Serves B2B industrial manufacturers with heat-intensive sites, including glass, ceramics and brick producers, targeting energy, sustainability and engineering teams responsible for heat…
Financial Health
StrongStrong · Growing, Hiring · 19% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsOperates test sites and infrastructure for wave and tidal energy devices, providing grid-connected marine energy testing, environmental monitoring and performance data. Delivers research and…
Serves wave, tidal and offshore renewable energy developers, technology companies, utilities, research consortia and public-sector stakeholders seeking marine energy testing, data and R&D support.
Financial Health
StableStable · -68% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 4 filingsProvides energy reduction technologies for commercial and industrial sites, including voltage optimisation and stabilisation systems, IoT-based energy management platforms, refrigeration energy…
Serves UK businesses and organisations with high energy use, including restaurants, pubs, hotels, manufacturers, commercial property managers, venues, schools, universities, gyms, leisure operators,…
Financial Health
HealthyHealthy · Hiring · 113% CAGR over 3y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 2 filingsDevelops and delivers renewable energy generation projects, including onshore wind farms, solar farms and battery energy storage systems. Works with public sector partners and stakeholders to plan,…
Serves Welsh public sector bodies, local communities and stakeholders involved in public-estate renewable energy projects, with benefits intended for people living and working across Wales.
Financial Health
HealthyHealthy · Hiring · 80% CAGR over 1y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDevelops and delivers low‑carbon energy and decarbonisation projects, including hydrogen production, carbon capture and storage, and biomethane initiatives. Provides technical, commercial and project…
Serves large industrial, energy, transport and heating-sector organisations, plus project partners and clients involved in UK net-zero hydrogen, carbon capture and low-carbon infrastructure…
Financial Health
StableStable · Hiring · 15% CAGR over 5y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDevelops and commercialises cleantech projects and technologies. Provides technical and commercial consultancy, project development, engineering and asset management services. Designs proprietary…
Serves B2B cleantech technology companies, project developers and asset owners, particularly wastewater, biosolids, biogas and waste-heat operators.
Financial Health
StrongStrong · Hiring · 24% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 2 filingsDevelops and invests in natural resource and energy infrastructure projects, including energy parks, district heat networks, and waste‑to‑value facilities. Focuses on repurposing land and resources…
Serves public- and private-sector partners involved in UK clean growth, circular economy, energy and infrastructure projects, including organisations seeking district heat networks, energy parks or…
Financial Health
StableStable
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsDevelops hardware and software platforms for monitoring and managing heat networks, boilers and heat pumps. Supplies smart metering hubs and analytics tools that capture energy and utility data,…
Serves residential developers, heat network operators, heat suppliers, and metering and billing providers managing communal heat networks and low-carbon heating systems across the UK.
Financial Health
WeakWeak · -17% CAGR over 2y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDesigns, installs and maintains building energy management and control systems for commercial properties. Provides system upgrades, integration, monitoring and maintenance to improve energy…
Serves B2B customers in the UK commercial property sector, including landlords, property owners, managing agents, asset management teams, consultants, project stakeholders and building occupiers…
Financial Health
StrongStrong · Growing, Hiring · 4% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDevelops, builds, and operates renewable energy projects, including utility-scale solar farms and battery storage. Provides project development, engineering, construction, and long-term operation of…
Serves UK landowners and farmers, corporates seeking renewable power purchase agreements, investors, local authorities and communities involved in utility-scale solar, wind and battery projects.
Financial Health
WeakWeak · 0% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDevelops, finances and operates on-site energy systems including combined heat and power plants, solar PV, energy storage, microgrids and heat networks. Provides energy centres and grid support…
Serves UK businesses and property developers in real estate, logistics, industrial, food and data centre sectors, especially organisations with high energy demand or grid capacity constraints.
Financial Health
HealthyHealthy · Hiring · 11% CAGR over 5y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDevelops low‑carbon and energy efficiency technologies for residential buildings, including shower water heat recovery systems and IoT home monitoring platforms that collect temperature and humidity…
Serves public and private sector housing organisations, including social landlords, housing providers and property managers responsible for resident homes, compliance, damp and mould risk, energy…
Financial Health
StrongStrong · Growing, Hiring · 79% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDesigns and builds district heating and cooling systems, including energy centres, distribution networks and energy substations. Provides engineering, installation and commissioning services for…
Serves UK clients commissioning district heating and cooling networks, including local authorities, commercial and residential developers, institutions, data centres and waste plants.
Financial Health
StrongStrong · Growing, Hiring · 63% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 4 filingsProvides energy efficiency retrofit and renewable energy installations, including wall and loft insulation, air source heat pumps, solar photovoltaic panels and EV chargers, delivering whole‑house…
Serves housing associations, local authorities, energy companies, managing agents, tier 1 contractors and public sector bodies delivering housing and public-space decarbonisation programmes across…
Financial Health
StrongStrong · Hiring · 91% CAGR over 2y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsDevelops and manages renewable energy projects focused on wind power. Provides feasibility studies, land leasing arrangements, installation, monitoring, and maintenance of wind turbines and battery…
Serves UK landowners, businesses and communities with wind energy assets, especially owners of underperforming turbines or sites in grid-constrained areas seeking renewable energy generation…
Financial Health
StableStable
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 4 filingsOperates anaerobic digestion facilities that convert food waste into biogas energy. Provides food waste collection and recycling services for hospitality and food producers, and runs…
Serves UK supermarkets, food producers and hospitality providers of all sizes, plus businesses with distribution and delivery needs requiring cold storage and food waste handling.
Financial Health
HealthyHealthy · Profitable · -77% CAGR over 3y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Develops, funds and manages small-scale energy‑from‑waste projects. Identifies sites, procures technology and operates facilities that process waste-derived fuels to generate heat and power, often…
Targets B2B organisations in the UK waste, recycling and renewable energy sectors, including recycling facility operators, energy-from-waste project owners and development companies.
Financial Health
N/AN/A
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDesigns and supplies smart hot water cylinders and energy storage systems for homes and commercial buildings. Products integrate with heat pumps, solar PV and energy grids, with software apps and…
Targets social housing providers, new-build housing developers, commercial estate owners/managers and utilities, with end users including homeowners and residents in low-carbon homes.
Financial Health
StableStable · -60% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDevelops thermal energy storage systems and compressor‑expander technology for industrial heat electrification. Designs systems that provide high‑ and low‑temperature thermal energy for processes…
Serves industrial organisations in hard-to-electrify sectors, including businesses with decarbonised heat, cooling, energy storage or drying applications, and partners pursuing clean energy projects.
Financial Health
StrongStrong · Growing, Hiring · 47% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsDevelops, invests in, and manages renewable energy projects including solar photovoltaic, onshore and offshore wind, battery energy storage, hybrid systems, and green hydrogen, providing project…
Serves municipalities, investors, landowners, farmers, and industrial or commercial businesses across Europe involved in renewable energy development, land use, and decarbonisation projects.
Financial Health
StableStable · Hiring · 36% CAGR over 2y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDevelops and manages energy infrastructure projects including flexible power generation plants, battery energy storage systems, and solar farms. Works with landowners and investors to identify sites,…
Targets UK landowners with suitable sites and investors seeking renewable energy, flexible generation, battery storage and solar farm opportunities; indirectly serves the UK electricity market and…
Financial Health
StableStable · -78% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsDevelops large-scale energy storage technologies and projects for renewable power, including hydrogen production and storage and compressed air energy storage (CAES). Designs systems using…
Serves energy-sector organisations and public bodies involved in renewable power, hydrogen, electricity and gas grids, interconnectors, and national energy security, including utilities, project…
Financial Health
HealthyHealthy · 0% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 4 filingsDesigns and installs commercial renewable energy systems including solar panel arrays, battery storage and electric vehicle charging infrastructure. Provides consultation, system integration and…
Serves UK businesses and company owners of varying sizes seeking commercial renewable energy, battery storage and EV charging options, including organisations looking for finance-based energy…
Financial Health
HealthyHealthy · -71% CAGR over 3y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 5 filingsProvides electric vehicle charging infrastructure including supply, installation and maintenance. Develops and installs energy management systems, LED energy‑efficient lighting, and LED traffic…
Serves SMEs, councils, large multi-site organisations and commercial property owners or managers in industrial, commercial and public-sector infrastructure environments.
Financial Health
WeakWeak · -75% CAGR over 4y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsDevelops electrochemical direct air capture technology that extracts carbon dioxide from the atmosphere. Supplies captured CO₂ for permanent geological storage or for use in products such as…
Serves B2B carbon removal project developers, CO₂ users, engineers and research partners in sectors including sequestration, sustainable building materials and e-fuels.
Financial Health
StableStable · -85% CAGR over 2y
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
Financial sub-scores
Computed from 3 filingsProvides operation, asset management, development and funding services for anaerobic digestion and biogas plants, including site operations, plant performance management, project development, and…
Serves B2B owners, investors and developers of anaerobic digestion, biogas and RNG plants, including organisations involved in organic treatment facilities and renewable energy projects.
Financial Health
DistressedDistressed
Location
Buy this list of 3,531 companies
The complete list in one Excel/CSV file — company details, websites and key data. Yours to download and use.
3,481 more companies and their verified directors are in the file
You’re seeing the top 50. Buy the list to get all 3,531 with directors, websites and financials.
How UK Cleantech companies work and how to sell to them
What they do
Most cleantech suppliers earn through a mix of project fees, equipment sales, recurring monitoring contracts, service agreements and, for software-led models, licences or subscriptions. Pricing often follows the asset being improved: per site, per meter, per sensor, per facility, per tonne processed or per monitored portfolio. Hardware and engineering firms tend to start with feasibility work, pilot installations or funded trials before moving into installation, maintenance and multi-site roll-out. Software and climate-data firms can look more like vertical SaaS businesses, though the value case still usually has to connect to energy cost, resource use, compliance evidence or operational resilience.
Who they sell to
Customers are usually mid-market, enterprise or public-sector organisations with estates, fleets, industrial processes, regulated assets or environmental reporting duties. Buying committees tend to include heads of energy, sustainability, estates, operations, engineering, procurement and finance, with technical approval often sitting close to site teams. Smaller software purchases may go through direct sales and departmental budgets; equipment, infrastructure and waste or water propositions more often face tenders, framework purchasing, safety reviews and site trials. Sales cycles are typically longer where installation risk, payback modelling or public procurement is involved, and shorter where the product audits existing operations rather than changing them.
What they buy
Most cleantech firms tend to spend on tools and services that help them prove performance, deliver projects and manage long sales cycles. Common software needs include CRM, bid management, billing, project management, field-service scheduling, asset monitoring, data warehousing, cyber security and finance systems that can handle grants, deposits, milestones and maintenance revenue. Engineering-heavy firms also buy prototyping support, certification advice, technical recruitment, health and safety services, insurance, supply-chain support and specialist accounting. Firms selling into public-sector or regulated buyers often need tender-writing help, legal review, environmental reporting support and customer-success processes that turn a single site win into a wider estate deployment.
Why and how to sell to them
Cleantech buyers tend to evaluate vendors when commercial proof becomes the constraint: pilots need converting into repeatable deployments, audits must withstand customer scrutiny, or operations teams need to deliver installations without tying up senior engineers. Useful triggers include funding, a new sustainability or operations hire, a move from trials into customer delivery, public-sector tender activity, headcount growth in sales or field roles, and evidence of moving beyond grant-funded work. Outbound angles usually work better when framed around payback evidence, delivery capacity, compliance traceability, working-capital control or shortening procurement steps, rather than broad climate claims.
How this list is built
Data sources
This list is built from UK Companies House filings, XBRL accounts data, and semantic analysis of each company's public website. Revenue and headcount figures come from the most recent filed accounts; where the company has not filed, values are estimated using a model trained on filed history and peer benchmarks and are labelled as estimates.
Classification
Rather than relying solely on SIC codes, Firmbase classifies each company semantically: the company's website is crawled, an AI model reads what the company actually sells, and the company is placed into the relevant industry and subsectors. SIC codes are used as one signal but not the only one. This means a company that registered under a generic SIC code but pivoted into (for example) fintech is correctly identified as fintech, not as its original SIC category.
Freshness
The underlying company data is refreshed from Companies House continuously; filings appear in the list within days of submission. The curated list ordering is regenerated when the underlying data moves meaningfully (company count changes by more than 5%, a new company enters the top-ranked segment, or the filed-revenue numbers for the top firms change). You can see the last-updated timestamp near the top of the page.
Also by city
Related directories
Frequently asked questions
How many cleantech companies are there in the UK?
What counts as a cleantech company in this list?
Which are the largest cleantech companies in the UK?
What do cleantech companies in the UK actually do?
How does UK cleantech compare internationally?
How is this list built and how fresh is the data?
How big are the typical cleantech companies in the UK?
Are these mostly new or established cleantech companies?
What SIC codes does this use?
What buying signals should I look for?
Buy all 3,531 companies as a spreadsheet.
One Excel/CSV file with company details, websites and key data — yours to download and use.