Top 100 Green Energy startups in UK
Mar 20, 2026
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28
1
Funding: $307.3M
Ceres Power develops solid oxide electrolysis cell and solid oxide fuel cell technologies for use in distributed energy systems for factories, data centers and electric vehicle charging stations. The company manufactures the entire stack - from cells (that it provides to OEM partners) to complete power systems that work on natural gas. These systems can produce up to 500 kW of power, with electrical efficiency up to 65%. According to the company, they also deliver 25% lower CO2 emissions than open-loop gas turbines and virtually zero NOx and SOx emissions. The systems are factory-transportable, withstand vibration and shock loads and are suitable for both indoor and outdoor installations.
Ceres Power develops solid oxide electrolysis cell and solid oxide fuel cell technologies for use in distributed energy systems for factories, data centers and electric vehicle charging stations. The company manufactures the entire stack - from cells (that it provides to OEM partners) to complete power systems that work on natural gas. These systems can produce up to 500 kW of power, with electrical efficiency up to 65%. According to the company, they also deliver 25% lower CO2 emissions than open-loop gas turbines and virtually zero NOx and SOx emissions. The systems are factory-transportable, withstand vibration and shock loads and are suitable for both indoor and outdoor installations.
2
Funding: $2.9B
Zenobe Energy manufactures battery energy storage systems. It provides comprehensive solutions for the electrification of fleets (buses, trucks and school transportation), including charging infrastructure, battery replacement and fleet management software. End-of-life vehicle batteries are given a second life in static battery systems. The company designs, finances, builds and operates large-scale battery storage systems, including Europe's largest 300 MW battery storage facility in Blackhillock, Scotland. Zenobe also supplies portable industrial BESS solutions powered by reconditioned batteries for construction sites and remote facilities.
Zenobe Energy manufactures battery energy storage systems. It provides comprehensive solutions for the electrification of fleets (buses, trucks and school transportation), including charging infrastructure, battery replacement and fleet management software. End-of-life vehicle batteries are given a second life in static battery systems. The company designs, finances, builds and operates large-scale battery storage systems, including Europe's largest 300 MW battery storage facility in Blackhillock, Scotland. Zenobe also supplies portable industrial BESS solutions powered by reconditioned batteries for construction sites and remote facilities.
3
Funding: $2.9B
Octopus Energy develops cloud-based smart grid platform and provides fair prices forever and greener energy from the UK's largest investor in solar generation. It uses an innovative AI and data-based platform to balance loads around the grid.
Octopus Energy develops cloud-based smart grid platform and provides fair prices forever and greener energy from the UK's largest investor in solar generation. It uses an innovative AI and data-based platform to balance loads around the grid.
4
Funding: $1B
Kraken is a spinoff of Octopus Energy, a company building a virtual grid for renewable energy supply. Kraken is the AI software that manages this grid, and Octopus has decided to sell it separately to other energy utilities. Kraken provides a suite of tools for managing the grid and customer base, forecasting load and income, organizing support and creating new products and tariffs. It also enables field operations management, including collaboration with local contractors, real-time network data retrieval to monitor performance, identify faults and allows to precisely manage capacity loads arising from the expansion of distributed energy sources. Kraken supplies its energy software to such utility companies as EDF and E.ON.
Kraken is a spinoff of Octopus Energy, a company building a virtual grid for renewable energy supply. Kraken is the AI software that manages this grid, and Octopus has decided to sell it separately to other energy utilities. Kraken provides a suite of tools for managing the grid and customer base, forecasting load and income, organizing support and creating new products and tariffs. It also enables field operations management, including collaboration with local contractors, real-time network data retrieval to monitor performance, identify faults and allows to precisely manage capacity loads arising from the expansion of distributed energy sources. Kraken supplies its energy software to such utility companies as EDF and E.ON.
5
Funding: $979.5M
Arrival is a technology company, that creates Generation 2 Electric Vehicles. Devices on wheels — they outperform legacy technology to deliver an experience like no other, but are priced the same as fossil fuel equivalents.
Arrival is a technology company, that creates Generation 2 Electric Vehicles. Devices on wheels — they outperform legacy technology to deliver an experience like no other, but are priced the same as fossil fuel equivalents.
6
Funding: £549.4M
ITM Power designs and manufactures proton-exchange membrane (PEM) electrolyzers for producing clean hydrogen using renewable electricity and tap water. Hydrogen produced by electrolysis is used in the transportation, Power-to-X projects and industrial processes. The company offers electrolyzers with capacities ranging from 2 to 50 MW. The units work with 30-bar pressure. Thanks to its very high current density, the technology reduces footprint and lowers costs. Combined with high conversion efficiency, it provides flexibility for optimizing project capital and operating costs. ITM has already deployed several commercial plants to customers and is using data to measure in-field product performance.
ITM Power designs and manufactures proton-exchange membrane (PEM) electrolyzers for producing clean hydrogen using renewable electricity and tap water. Hydrogen produced by electrolysis is used in the transportation, Power-to-X projects and industrial processes. The company offers electrolyzers with capacities ranging from 2 to 50 MW. The units work with 30-bar pressure. Thanks to its very high current density, the technology reduces footprint and lowers costs. Combined with high conversion efficiency, it provides flexibility for optimizing project capital and operating costs. ITM has already deployed several commercial plants to customers and is using data to measure in-field product performance.
7
Funding: $677.1M
Newcleo develops small modular reactors (SMRs) that uses MOX fuel technology to reprocess spent uranium from conventional nuclear power plants. The 200 MW reactor uses lead as a coolant. This is an ultra-compact module with improved energy density compared to other technologies. MOX fuel, which stands for Mixed Pu-U Oxides consists of depleted uranium (a byproduct of the enrichment process in modern reactors) and plutonium (which is extracted from spent nuclear fuel). The company intends to use already available nuclear material in France in synergy with the in-country environment. Newcleo plans to install the first 30 MW lead-cooled fast reactor (LFR-AS-30) in Savigny-en-Véron and Beaumont-en-Véron.
Newcleo develops small modular reactors (SMRs) that uses MOX fuel technology to reprocess spent uranium from conventional nuclear power plants. The 200 MW reactor uses lead as a coolant. This is an ultra-compact module with improved energy density compared to other technologies. MOX fuel, which stands for Mixed Pu-U Oxides consists of depleted uranium (a byproduct of the enrichment process in modern reactors) and plutonium (which is extracted from spent nuclear fuel). The company intends to use already available nuclear material in France in synergy with the in-country environment. Newcleo plans to install the first 30 MW lead-cooled fast reactor (LFR-AS-30) in Savigny-en-Véron and Beaumont-en-Véron.
8
Funding: £447M
OVO Energy is an independent energy technology company and supplier. OVO also installs world’s most advanced storage heaters
OVO Energy is an independent energy technology company and supplier. OVO also installs world’s most advanced storage heaters
10
Funding: $445.5M
Highview Power’s CRYOBattery delivers, clean, reliable, and cost-efficient long-duration energy storage to enable a 100% renewable energy future. It is storing energy in “liquid air”—when you compress a gas enough, it turns liquid
Highview Power’s CRYOBattery delivers, clean, reliable, and cost-efficient long-duration energy storage to enable a 100% renewable energy future. It is storing energy in “liquid air”—when you compress a gas enough, it turns liquid
11
Funding: £287M
Field is a renewable energy company aiming to accelerate the build-out of renewable infrastructure needed to reach net zero. It is building battery storage projects across the UK
Field is a renewable energy company aiming to accelerate the build-out of renewable infrastructure needed to reach net zero. It is building battery storage projects across the UK
12
Funding: $330.9M
Nexeon is an electronics company that develops and manufactures lithium-ion batteries to reduce carbon anode energy inefficiency.
Nexeon is an electronics company that develops and manufactures lithium-ion batteries to reduce carbon anode energy inefficiency.
13
Funding: $292M
Pulse Clean Energy builds and operates power stations. We deliver power into the UK’s network when it is most needed.
Pulse Clean Energy builds and operates power stations. We deliver power into the UK’s network when it is most needed.
14
Funding: $287M
Tokamak Energy aims to accelerate the development of fusion energy. Tokamak Energy was founded by leading scientists from the world’s leading fusion research establishment at Culham to develop the potential to use fusion neutrons for a variety of applications from material treatments to medical applications or low cost hydrogen production. The technology is also applicable in the area of nuclear waste, where it...
Tokamak Energy aims to accelerate the development of fusion energy. Tokamak Energy was founded by leading scientists from the world’s leading fusion research establishment at Culham to develop the potential to use fusion neutrons for a variety of applications from material treatments to medical applications or low cost hydrogen production. The technology is also applicable in the area of nuclear waste, where it...
15
Funding: £200M
Deep Green has developed a “digital boiler” technology to use the heat produced by data centers for swimming pools, apartment blocks, distilleries, laundrettes, and bakeries.
Deep Green has developed a “digital boiler” technology to use the heat produced by data centers for swimming pools, apartment blocks, distilleries, laundrettes, and bakeries.
16
Funding: $231.8M
Venterra engineer, build, and support the operations of wind energy developments around the world.
Venterra engineer, build, and support the operations of wind energy developments around the world.
17
Funding: $215M
BBOXX designs, manufactures, and distributes plug and play solar systems. It also offers pay-as-you-go solar power. BBOXX Power DC product range is closed DC systems in standardised sizes. BBOXX Hub brings the smart capabilities of remote monitoring and control to larger capacity systems and projects. BBOXX Pulse is a comprehensive management platform that enables growth of next generation utility businesses.
BBOXX designs, manufactures, and distributes plug and play solar systems. It also offers pay-as-you-go solar power. BBOXX Power DC product range is closed DC systems in standardised sizes. BBOXX Hub brings the smart capabilities of remote monitoring and control to larger capacity systems and projects. BBOXX Pulse is a comprehensive management platform that enables growth of next generation utility businesses.
18
Funding: $152.2M
Oxford PV develops perovskite tandem cell technology - solar cells that consist of two components: one perovskite and the other silicon. Traditional silicon solar cells absorb light in the red part of the spectrum, while perovskite absorbs light in the blue part. Thus, a tandem cell captures more sunlight than a single cell can, and therefore generates more energy. All this without changing the size (area) of the solar cell. Oxford PV's proprietary perovskite technology is designed to work with standard solar panels. The company has its own manufacturing facility and sets new world records for perovskite cells efficiency almost every year.
Oxford PV develops perovskite tandem cell technology - solar cells that consist of two components: one perovskite and the other silicon. Traditional silicon solar cells absorb light in the red part of the spectrum, while perovskite absorbs light in the blue part. Thus, a tandem cell captures more sunlight than a single cell can, and therefore generates more energy. All this without changing the size (area) of the solar cell. Oxford PV's proprietary perovskite technology is designed to work with standard solar panels. The company has its own manufacturing facility and sets new world records for perovskite cells efficiency almost every year.
19
Funding: £100M
Aegis Energy is building a network of 50 environmentally friendly multi-purpose charging stations across the UK (with a goal of 30 by 2030). The network is specifically designed for commercial vehicles (trucks and vans) and offers electric charging, HVO, hydrogen and bio-CNG. The stations feature dedicated parking for oversized and non-standard cargos and trucks. Drivers are provided with a mobile app to find the nearest station, monitor and control the charging process and pay for charging sessions with a single click. While their vehicles are charging, drivers can use clean toilets and showers, enjoy quality food and relax in quiet rest areas.
Aegis Energy is building a network of 50 environmentally friendly multi-purpose charging stations across the UK (with a goal of 30 by 2030). The network is specifically designed for commercial vehicles (trucks and vans) and offers electric charging, HVO, hydrogen and bio-CNG. The stations feature dedicated parking for oversized and non-standard cargos and trucks. Drivers are provided with a mobile app to find the nearest station, monitor and control the charging process and pay for charging sessions with a single click. While their vehicles are charging, drivers can use clean toilets and showers, enjoy quality food and relax in quiet rest areas.
20
Funding: $113.6M
Nyobolt is a developer of high-powered battery technology used to serve automotive applications.
Nyobolt is a developer of high-powered battery technology used to serve automotive applications.
21
Funding: $107M
First Light Fusion (FLF) develops Inertial confinement fusion reactor that can produce power.
First Light Fusion (FLF) develops Inertial confinement fusion reactor that can produce power.
22
Funding: $100.7M
Fuse Energy offers commission-free energy; 10x cheaper; 10x better, and 100 per cent renewable energy.
Fuse Energy offers commission-free energy; 10x cheaper; 10x better, and 100 per cent renewable energy.
23
Funding: $91.9M
tem is developing RED - an AI platform for the energy market that helps companies purchase clean, renewable energy directly from producers, reducing dependence on wholesalers and energy brokers and transforming the way electricity is purchased and sold. This platform is the transaction layer that underlies how energy is priced and settled. Companies that use half-hourly meter and can switch supplier - are ready to connect to RED and start saving up to 30%. tem also helps generating companies earn more through transparent pricing, fast quotes and reliable, timely payments. To date, the company has processed over 2 TWh of energy transactions in the UK.
tem is developing RED - an AI platform for the energy market that helps companies purchase clean, renewable energy directly from producers, reducing dependence on wholesalers and energy brokers and transforming the way electricity is purchased and sold. This platform is the transaction layer that underlies how energy is priced and settled. Companies that use half-hourly meter and can switch supplier - are ready to connect to RED and start saving up to 30%. tem also helps generating companies earn more through transparent pricing, fast quotes and reliable, timely payments. To date, the company has processed over 2 TWh of energy transactions in the UK.
24
Funding: £70M
Domna provides retrofit assessment software that predicts works programme, maximising energy efficiency services to housing properties.
Domna provides retrofit assessment software that predicts works programme, maximising energy efficiency services to housing properties.
25
Funding: $87.8M
Ev.energy is a smart charging software platform for electric vehicles to reduce carbon emissions and costs.
Ev.energy is a smart charging software platform for electric vehicles to reduce carbon emissions and costs.
26
Funding: $86.5M
Origami Energy is creating a real-time marketplace for a distributed energy world. It's smart technology intelligently manages and remotely controls distributed energy assets to access the most profitable current and future value opportunities.
Origami Energy is creating a real-time marketplace for a distributed energy world. It's smart technology intelligently manages and remotely controls distributed energy assets to access the most profitable current and future value opportunities.
27
Funding: £60M
My Energi makes Electric Vehicle charging equipment and eco-smart home devices.
My Energi makes Electric Vehicle charging equipment and eco-smart home devices.
28
Funding: $73.3M
Engineered to cool the whole IT stack, in every use case, from Hyperscale to the Extreme Edge
Engineered to cool the whole IT stack, in every use case, from Hyperscale to the Extreme Edge
29
Funding: $73M
Addionics is creating next-generation batteries for electric cars through intelligent 3D battery architecture and engineering.
Addionics is creating next-generation batteries for electric cars through intelligent 3D battery architecture and engineering.
30
Funding: $57.8M
Bramble Energy is an innovator energy technology company that designs and manufactures high-performance, low-cost, and fuel cell stack
Bramble Energy is an innovator energy technology company that designs and manufactures high-performance, low-cost, and fuel cell stack
31
Funding: £41.8M
Trojan Energy develops a system that offers an equal chance for EV drivers without a driveway to charge effectively at home, while eliminating residual clutter on the pavement.
Trojan Energy develops a system that offers an equal chance for EV drivers without a driveway to charge effectively at home, while eliminating residual clutter on the pavement.
32
Funding: $46.1M
Moixa is the UK’s leading smart battery company. We develop our Smart Battery hardware and GridShare software to facilitate smart energy storage and sharing.
Moixa is the UK’s leading smart battery company. We develop our Smart Battery hardware and GridShare software to facilitate smart energy storage and sharing.
33
Funding: $43.5M
Sunamp is a company that provides industrial and residential heat battery storage systems.
Sunamp is a company that provides industrial and residential heat battery storage systems.
34
Funding: £35M
Exagen Group is building the next generation of utility scale solar farms co-located with grid-balancing battery storage facilities.
Exagen Group is building the next generation of utility scale solar farms co-located with grid-balancing battery storage facilities.
35
Funding: $33M
Breathe Battery Technologies is a developer of electric vehicle battery charging control software for automotive manufacturers.
Breathe Battery Technologies is a developer of electric vehicle battery charging control software for automotive manufacturers.
36
Funding: £26M
HiiROC is an industrial company that produces hydrogen from biomethane, flare gas, or natural gas with no CO2 emissions.
HiiROC is an industrial company that produces hydrogen from biomethane, flare gas, or natural gas with no CO2 emissions.
37
Funding: $31.9M
Scotrenewables Tidal Power is a renewable energy research and development company focused on tidal power.
Scotrenewables Tidal Power is a renewable energy research and development company focused on tidal power.
38
Funding: £24.4M
Naked Energy has developed an innovative hybrid solar technology generating combined heat and power.
Naked Energy has developed an innovative hybrid solar technology generating combined heat and power.
39
Funding: £24M
3D vision and artificial intelligence applied to subsea robotics servicing offshore wind decommissioning
3D vision and artificial intelligence applied to subsea robotics servicing offshore wind decommissioning
40
Funding: £21.4M
QiO Technologies is an AI sustainability tech company that provides a sustainability suite to reduce greenhouse gas emissions.
QiO Technologies is an AI sustainability tech company that provides a sustainability suite to reduce greenhouse gas emissions.
41
Funding: $21.7M
Fuuse is innovating the charging infrastructure landscape by developing an operating system for organisations and their EV chargers, with a mission to eliminate barriers to EV adoption and accelerate the shift towards sustainable transportation.
Fuuse is innovating the charging infrastructure landscape by developing an operating system for organisations and their EV chargers, with a mission to eliminate barriers to EV adoption and accelerate the shift towards sustainable transportation.
42
Funding: £16.1M
Providing a data-driven energy platform, Modo Energy is emerging as one of the key players in optimising energy storage.
Providing a data-driven energy platform, Modo Energy is emerging as one of the key players in optimising energy storage.
43
Funding: £15.9M
Piclo develops software to make electricity grids smart, flexible and sustainable.
Piclo develops software to make electricity grids smart, flexible and sustainable.
44
Funding: $17.5M
Volteras collects, standardizes, and optimizes data from hundreds of energy devices into a single data model.
Volteras collects, standardizes, and optimizes data from hundreds of energy devices into a single data model.
45
Funding: £14M
ReEnergise developed High-Density Hydro technology to create pumped hydro energy storage systems that can be located in low-lying, hilly terrain, eliminating the need for high, steep slopes. The HD Hydro system uses a dense, mineral-rich liquid instead of water to reduce the system's size while delivering the same performance as a much larger system using regular water. The liquid recirculates through a pipeline between the upper and lower reservoirs. The compact size of the HD Hydro system allows for burying one or both reservoirs underground, preserving the land above for other uses. With an eight-hour operating cycle, this high-density hydropower system is half the cost of a lithium-ion battery system, without the risk of fire or environmental concerns. The company has already implemented a pilot project at Cornwood, a kaolin mine in the UK.
ReEnergise developed High-Density Hydro technology to create pumped hydro energy storage systems that can be located in low-lying, hilly terrain, eliminating the need for high, steep slopes. The HD Hydro system uses a dense, mineral-rich liquid instead of water to reduce the system's size while delivering the same performance as a much larger system using regular water. The liquid recirculates through a pipeline between the upper and lower reservoirs. The compact size of the HD Hydro system allows for burying one or both reservoirs underground, preserving the land above for other uses. With an eight-hour operating cycle, this high-density hydropower system is half the cost of a lithium-ion battery system, without the risk of fire or environmental concerns. The company has already implemented a pilot project at Cornwood, a kaolin mine in the UK.
46
Funding: £14M
Cheesecake Energy is developing advanced thermal and compressed air energy systems to store energy.
Cheesecake Energy is developing advanced thermal and compressed air energy systems to store energy.
47
Funding: $16.9M
Verv is an intelligent home hub, which gives the power to take control of energy usage to ultimately reduce energy bills.
Verv is an intelligent home hub, which gives the power to take control of energy usage to ultimately reduce energy bills.
48
Funding: £13.5M
Immaterial develops metal-organic frameworks (MOFs) that exhibit ultra-high hydrogen storage efficiency. MOFs are made of porous coordination polymers - carefully selected components, when mixed together, self-assemble into a precise lattice structure with metal ions at each corner and organic linkers at each edge. The company can design MOFs with highly specific pore sizes, surface chemistry and wide range of other physical properties, depending on needs. They use molecular modeling methods to select the most effective material and solve the customer's "problem" based on a combination of system performance metrics and other relevant properties not covered by computational screening, such as chemical stability, strength and ease of synthesis.
Immaterial develops metal-organic frameworks (MOFs) that exhibit ultra-high hydrogen storage efficiency. MOFs are made of porous coordination polymers - carefully selected components, when mixed together, self-assemble into a precise lattice structure with metal ions at each corner and organic linkers at each edge. The company can design MOFs with highly specific pore sizes, surface chemistry and wide range of other physical properties, depending on needs. They use molecular modeling methods to select the most effective material and solve the customer's "problem" based on a combination of system performance metrics and other relevant properties not covered by computational screening, such as chemical stability, strength and ease of synthesis.
49
Funding: £12.3M
Continuum Industries offers a cloud-based platform designed to accelerate and de-risk the development of new linear infrastructure projects, from concept to consent. They streamline optioneering for various infrastructure types, including electricity transmission, renewable energy, hydrogen, and water networks.
Continuum Industries offers a cloud-based platform designed to accelerate and de-risk the development of new linear infrastructure projects, from concept to consent. They streamline optioneering for various infrastructure types, including electricity transmission, renewable energy, hydrogen, and water networks.
50
Funding: £12.8M
AssetCool produces photonic coatings and materials that enhance the functionality of electrical networks.
AssetCool produces photonic coatings and materials that enhance the functionality of electrical networks.
