Ranked by the ClimateTicker Green Score — who genuinely helps, and who to watch.
Climate Software · San Francisco, CA, USA
Enterprise carbon-management platform that helps large companies measure, report and reduce emissions across their operations and supply chains.
Carbon Removal · Zurich, Switzerland
Swiss pioneer of direct air capture (DAC), removing CO₂ from the atmosphere and storing it permanently underground, including the Orca and Mammoth plants in Iceland.
Solar · San Francisco, CA, USA· RUN
Largest residential solar, battery storage and energy-services company in the United States, offering home solar through subscription and ownership models.
Energy · London, UK
UK-based clean energy retailer and technology group whose Kraken platform manages renewable supply, smart tariffs and grid flexibility for millions of customers worldwide.
Transport · Irvine, CA, USA· RIVN
American electric vehicle manufacturer producing adventure-focused trucks and SUVs, plus commercial electric delivery vans, with a vertically integrated software and charging ecosystem.
Wind turbines · Aarhus, Denmark· VWS
World's largest wind-turbine manufacturer by installed capacity.
Offshore wind / renewable energy · Fredericia, Denmark· ORSTED
World's largest offshore wind developer, formerly DONG Energy; majority-owned by the Danish state.
Onshore wind · Hamburg, Germany· NDX1
German wind turbine manufacturer supplying multi-megawatt onshore turbines across Europe, the Americas, Africa, and Asia.
Offshore wind development · Lisbon, Portugal· EDPR
Listed subsidiary of EDP and one of Europe's largest renewable energy companies, developing offshore wind capacity in France, Portugal, and the UK including the Moray West project in Scotland.
Solar panels / thin-film PV · Tempe, Arizona, United States· FSLR
Leading US manufacturer of thin-film cadmium telluride solar panels; one of the few Western solar manufacturers at scale.
Solar · Oslo, Norway· SCATC
Norwegian renewable energy company developing, building, owning and operating utility-scale solar, wind and hydropower projects across emerging and developed markets.
Integrated utility · Vienna, Austria· VER
Austria's dominant electricity provider, generating ~90% of output from 108 hydropower plants with 6,600 MW installed capacity and ~24.8 TWh average annual hydro generation; 51% owned by the Austrian state.
Bank · New York, US· AMAL
US progressive bank that excludes fossil-fuel lending, serves union and non-profit clients, and is a signatory to the UN Principles for Responsible Banking and the Net-Zero Banking Alliance.
Heating controls & components · Nordborg, Denmark
Danish industrial group making heat pump compressors, refrigerant systems, and thermostatic controls that enable energy-efficient heating and cooling across residential and commercial buildings.
Recycling / circular · Asker, Norway· TOM
Norwegian circular-economy technology group operating over 91,000 reverse vending machines for bottle and can returns, plus AI-driven sensor sorting systems for recycling and food industries worldwide.
Integrated utility · Espoo, Finland· FORTUM
Finnish state-majority utility with ~47 TWh low-carbon annual portfolio from hydro (4,653 MW across 33 plants) and nuclear (Loviisa plant, licensed to 2050), with a growing wind pipeline in the Nordics.
Grid / transmission & distribution · London, UK
UK Power Networks is the licensed electricity distribution network operator serving London, the South East, and East of England, connecting over eight million customers and leading DSO transformation to host distributed renewables.
Integrated utility · Bilbao, Spain· IBE
Spain's largest utility and a global renewables leader, with 23,047 MW of renewable capacity in Spain and a €58bn 2025–2028 investment plan overwhelmingly directed at wind, solar and grid infrastructure.
Asset manager · London, UK· IPX
London-listed specialist asset manager investing in companies providing resources and environmental services in the energy transition, water, waste, and sustainable food sectors.
Offshore wind cables · Paris, France· NEX
French cable technology group and a leading supplier of inter-array and export submarine cables for offshore wind farms, operating the dedicated cable-lay vessel Aurora.
Solar · Hamburg, Germany
German independent power producer operating a large portfolio of solar and wind parks across Europe, taken private by KKR in 2024.
Carbon accounting · Stockholm, Sweden
Carbon accounting platform with a TÜV SÜD-evaluated engine covering 349,000 verified emission factors, serving enterprise customers across the Nordics and EU.
Green Infrastructure Fund · London, UK
Schroders-owned specialist renewable energy infrastructure manager running listed funds including Greencoat UK Wind (UKW) and Greencoat Renewables, investing exclusively in operating wind and solar assets.
Hydrogen fuel cells · Burnaby, Canada· BLDP
Canadian PEM fuel cell pioneer supplying zero-emission hydrogen fuel cells for buses, trucks, trains, marine vessels and stationary power applications worldwide.
Carbon removal · London, UK
London carbon intelligence platform rating voluntary carbon credits AAA–D using satellite data, LiDAR, and machine learning to bring independent MRV and transparency to carbon markets.
Integrated utility · Paris, France
France's fully state-owned electricity giant generating 373 TWh of nuclear power in 2025; overall output is 94% decarbonised with a carbon intensity of 30 gCO₂/kWh, making it Europe's largest low-carbon generator.
Carbon removal · Reykjavik, Iceland
Icelandic company that permanently mineralises CO₂ by dissolving it in water and injecting it into basaltic rock, where it solidifies into stone within two years rather than millennia.
Offshore wind cables · Milan, Italy· PRY
Italian cable and systems manufacturer that is a leading supplier of high-voltage submarine cables and turnkey cable systems connecting offshore wind farms to shore across Europe and beyond.
Grid / transmission & distribution · Arnhem, Netherlands
TenneT is the electricity transmission system operator for the Netherlands and a large part of Germany, managing high-voltage grids and cross-border power flows critical to integrating North Sea offshore wind capacity.
Onshore wind · Genoa, Italy· ERG
Italian energy company that transitioned from oil refining to become one of Italy's largest onshore wind operators, with assets across Europe.
Carbon removal · Brisbane, CA, USA
US DAC company that accelerates the natural carbon mineralisation of limestone from years to days, with its first commercial facility in California and a second announced in Louisiana.
Heat pumps · Markaryd, Sweden· NIBE-B
Swedish manufacturer of heat pumps and energy-efficient climate systems for residential and commercial buildings across Europe and North America.
Offshore wind turbines · Zamudio, Spain
World-leading offshore wind turbine manufacturer producing the SG 14-236 DD platform, with factories and service operations across the UK and Europe; wholly owned by Siemens Energy since 2023.
Solar · Madrid, Spain· SLR
Spanish solar developer and operator focused exclusively on large-scale photovoltaic projects across Spain, Italy, Portugal and Greece.
Green Infrastructure Fund · Annapolis, MD, US· HASI
US-listed REIT and infrastructure investor exclusively deploying capital into climate solutions including wind, solar, energy efficiency, and sustainable land assets.
Grid / transmission & distribution · Brussels, Belgium· ELI
Belgium's national electricity transmission system operator, also controlling 50Hertz — one of Germany's four TSOs — enabling the integration of large-scale offshore wind and cross-border renewable energy flows.
Recycling / circular · Brussels, Belgium· UMI
Belgian materials technology and recycling group that recovers precious and base metals from complex e-waste and industrial residues, and produces battery cathode materials for electric vehicles.
Water technology · Washington, US· XYL
Xylem designs and manufactures water and wastewater technology — from smart meters and network management to treatment and analytics — serving utilities, industry, and municipalities across 150+ countries.
Carbon removal · San Francisco, CA, USA
US company converting agricultural biomass into carbon-rich bio-oil via fast pyrolysis, then permanently sequestering it by injecting it into deep geological formations.
Carbon accounting · Paris, France
SaaS carbon accounting platform enabling companies to automate GHG measurement across Scope 1, 2, and 3 using a library of 300,000+ emission factors, with compliance support for CSRD and GHG Protocol.
Solar · Fremont, CA, US· NXT
Designs and manufactures intelligent solar tracker systems and software for utility-scale solar projects worldwide.
ESG software · Chicago, US
Integrated ESG, environment-health-safety, operational risk, and product stewardship software platform serving 8,500 customers in 100 countries, acquired by Blackstone in 2021 at a $1.4B valuation.
Green hydrogen · Dortmund, Germany· NCH2
German alkaline water electrolysis specialist offering industrial-scale electrolyser plants for green hydrogen production, spun out of thyssenkrupp and listed on Frankfurt in 2023.
Nature-based solutions · Edinburgh, United Kingdom
UK's leading developer of Woodland Carbon Code and Peatland Code projects, having funded 13M+ trees planted and 2,000 hectares of peatland restored; became employee-owned in 2023.
Carbon accounting · Tempe, US
AI-driven carbon accounting and climate management SaaS platform helping companies and financial institutions measure, disclose, and manage their Scope 1, 2, and 3 emissions.
EV Maker · Gothenburg, Sweden· PSNY
Swedish pure-play EV brand co-owned by Volvo Cars and Geely, producing the Polestar 2–4 electric vehicles and notable for industry-leading lifecycle carbon transparency.
Offshore wind foundations · Maasvlakte, Rotterdam, Netherlands· SIFG
Dutch steel manufacturer specialising exclusively in offshore wind monopile and transition-piece foundations, supplying projects across the North Sea and Baltic from its deep-water Maasvlakte facility.
Solar · Paris, France· VLTSA
French independent power producer developing, building and operating solar, wind, hydropower and storage projects across Europe, Africa and Latin America.
Sustainable aviation fuel · Boston, US
North America's first and longest-operating commercial-scale SAF producer, supplying biofuel made from inedible agricultural waste to aviation and other hard-to-abate sectors.
Supply chain emissions · London, UK
Sustainability data management platform automating Scope 1, 2, and 3 emissions measurement and product carbon footprinting for complex enterprises in food, drink, and packaging sectors.
Green hydrogen · Hamburg, Germany· H2O
German cleantech company developing and manufacturing AEM (Anion Exchange Membrane) electrolysers for scalable, iridium-free green hydrogen production at industrial scale.
Energy storage · London, UK
UK-based battery storage developer and operator with over 1.2 GW of BESS projects including the 300 MW Kilmarnock South and 400 MW Eccles sites, backed by KKR with cumulative funding exceeding £1 billion.
Integrated utility · Rome, Italy· ENEL
Italy's largest power utility and one of the world's biggest integrated operators, with 16.9 GW renewable capacity in Italy alongside 11.3 GW of thermal; committed to phasing out fossil gas by 2040.
Green Infrastructure Fund · London, UK· FSG
London-listed infrastructure and private equity investment manager with a large renewable energy portfolio spanning solar, wind, battery storage, and bioenergy assets across Europe and beyond.
Grid / smart-grid & metering technology · Liberty Lake, Washington, USA· ITRI
Itron delivers smart meters, network infrastructure, and grid-edge analytics that enable utilities to optimise energy delivery, reduce losses, and integrate distributed renewable energy resources.
Onshore wind · London, UK
UK-based renewable energy investment and development platform focused on onshore wind, solar, and battery storage projects in Britain and internationally.
Electricity transmission / grid infrastructure · London, United Kingdom· NG.
Operates the UK's high-voltage electricity transmission network and US electricity and gas distribution businesses.
Electricity generation / networks · Perth, Scotland, United Kingdom· SSE
UK-based energy company with a large renewables portfolio (onshore/offshore wind, hydro) and electricity networks; one of the UK's leading clean-energy investors.
Reinsurer · Zurich, Switzerland· SREN
One of the world's two largest reinsurers, a pioneer in climate-risk modelling and parametric insurance products, and committed to ceasing coverage of new oil-sands and coal projects.
Integrated utility · Solna, Sweden
Swedish state-owned utility with a largely fossil-free generation mix (hydro, nuclear and wind); planning small modular reactor (SMR) expansion.
Grid / smart-grid & VPP software · London, UK
Kraken Technologies — an Octopus Energy Group subsidiary — provides a cloud-native energy retail and grid flexibility operating system licensed to utilities worldwide, enabling demand response, smart tariffs, and distributed energy resource management at scale.
Climate VC · San Francisco, CA, US
San Francisco-based venture firm backing companies transforming energy, transportation, food, and agriculture systems to address climate change.
Heat pumps · Remscheid, Germany
German heating manufacturer pivoting aggressively to heat pumps — opened a dedicated heat pump mega-factory in 2024 — but continues to produce gas boilers alongside its growing heat pump range.
Hydrogen fuel cells · Horsham, UK· CWR
UK developer of proprietary solid oxide cell technology licensed to global manufacturers for both distributed power generation and green hydrogen electrolysis.
Climate VC · Boston, MA, US
Early-stage climate tech VC focused on deep-decarbonisation ventures in energy, transportation, agriculture, and industrial sectors with high emissions-reduction potential.
Climate VC · New York, NY, US
Utility-backed cleantech growth VC partnering with energy companies and investors to accelerate the transition to a sustainable energy future.
Energy storage · Westlake Village, CA, US· NRGV
Develops gravity-based and battery energy storage systems alongside an energy management software platform for utilities, IPPs, and industrial and data-centre clients.
Grid / equipment & technology · Munich, Germany· ENR
Siemens Energy — spun off from Siemens AG in 2020 — provides high-voltage grid technologies, power transformers, HVDC systems, and energy management software essential for transmission infrastructure serving renewable generation.
Sustainable aviation fuel · Amsterdam, Netherlands
Dutch SAF supply and production company co-founded by KLM that supplied the world's first commercial SAF flight in 2011 and is developing production facilities across the Netherlands, Sweden, and the US.
Energy storage · London, UK· GRID
UK's largest listed fund investing in utility-scale battery energy storage systems, operating over 1 GW of BESS capacity across Great Britain and internationally.
Solar · London, UK
UK-headquartered solar energy developer and operator with a global portfolio of utility-scale solar and storage projects, majority-owned by bp.
Solar · Singapore
Singapore-based producer of high-efficiency back-contact solar panels under the Maxeon brand for residential and commercial markets globally.
Physical climate risk intelligence · Barcelona, Spain
Mitiga Solutions is a Barcelona Supercomputing Center spin-off that delivers AI-powered physical climate risk models — covering floods, heatwaves, wildfires, and more — to help insurers, banks, and corporates assess and disclose climate-related asset exposure.
Grid / transmission & distribution · Penshaw, Sunderland, UK
Northern Powergrid operates the electricity distribution network for northeast England and Yorkshire, serving approximately 3.9 million homes and businesses and investing in network modernisation to support electrification of heat and transport.
EV charging
UK rapid EV charging network (originally founded as Engenie) operating over 1,300 rapid chargers at 380+ locations, powered by 100% renewable energy.
Nuclear / SMR · Stoke Poges, United Kingdom
Urenco is a multinational uranium enrichment company jointly owned by the UK, Dutch, and German governments, operating centrifuge plants in the UK, Netherlands, Germany, and US and supplying roughly 30% of global enriched uranium.
Low-carbon cement · Oakland, USA
Oakland startup producing ordinary portland cement from calcium silicate rocks instead of limestone, eliminating process CO2 emissions and permanently storing calcium carbonate within the final product.
Solar · Guelph, ON, Canada· CSIQ
Vertically integrated solar company manufacturing panels and developing utility-scale solar and battery storage projects across more than 20 countries.
Geothermal · Houston, United States· FRVO
Enhanced geothermal energy company applying directional drilling and fiber-optic sensing to access hot rock, with Cape Station in Utah delivering 100 MW of firm clean power to the grid from 2026.
Climate VC · New York, NY, US
Climate-focused investment firm co-founded by Tom Steyer and Katie Hall deploying across growth equity, venture, and infrastructure to accelerate the net-zero transition.
Tidal energy · Edinburgh, United Kingdom
Developer of floating tidal stream turbines, operating the O2 — the world's highest-rated tidal energy device at 2 MW — off Orkney, with a 32 MW combined orderbook across the UK and Canada.
Recycling / circular · Milton Keynes, United Kingdom· RWI
Anglo-Dutch waste-to-product company that collects, treats, and transforms commercial, industrial, and hazardous waste into secondary raw materials across the UK, Netherlands, Belgium, and France.
Offshore wind installation · Stavanger, Norway
Dedicated offshore wind EPCI contractor and wholly owned subsidiary of Subsea 7, executing foundation, cable, and turbine installation contracts for major North Sea and European offshore wind projects.
Low-carbon cement · Somerville, USA
MIT-founded startup producing portland cement via electrochemistry rather than fossil-fuel kilns, avoiding the process CO2 that accounts for roughly half of conventional cement's emissions.
ESG data · Paris, France
Carbon and ESG data management platform used by multinationals including L'Oreal and Thales to collect, manage, and report sustainability data across frameworks including CSRD and ISSB.
Insurer · Paris, France· AXA
Global insurer that was among the first major institutional investors to divest from coal and tar sands, and has committed over €26 billion to green investments as part of its Net Zero 2050 roadmap.
Supply chain sustainability · Paris, France
Global supply chain sustainability ratings platform assessing 175,000+ suppliers across 180 countries using AI combined with 500+ in-house analysts, trusted by 1,500+ global procurement leaders.
Integrated utility · Karlsruhe, Germany· EBK
Germany's third-largest utility, post-nuclear since Neckarwestheim II decommissioned in 2023; deploying a €50bn 2025–2030 programme heavily weighted to renewables with gas plants retained as hydrogen-convertible bridge capacity.
Offshore wind installation · Hofstade-Aalst, Belgium
Belgian family-owned dredging and marine engineering contractor with a large fleet specialised in offshore wind cable installation and foundation work, active on major European and international projects.
Agritech · San Francisco, CA, US
Uses solar-powered plasma technology to fix atmospheric nitrogen and convert agricultural organic waste (including almond shells) into low-emission organic fertilisers for row-crop growers.