Top 100 Green Energy startups in UK

Jan 06, 2026
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1
Ceres Power
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.
2
Octopus Energy
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.
3
Zenobe Energy
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.
4
Kraken
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.
5
Arrival
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.
6
Newcleo
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.
7
Ovo Energy
Funding: £447M
OVO Energy is an independent energy technology company and supplier. OVO also installs world’s most advanced storage heaters
8
Hometree
Funding: $468.9M
Hometree operates as an online-led boiler installation company.
9
Highview Power
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
10
Field
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
11
Nexeon
Funding: $330.9M
Nexeon is an electronics company that develops and manufactures lithium-ion batteries to reduce carbon anode energy inefficiency.
12
Pulse Clean Energy
Funding: $292M
Pulse Clean Energy builds and operates power stations. We deliver power into the UK’s network when it is most needed.
13
Tokamak Energy
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...
14
Deep Green
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.
15
Venterra
Funding: $231.8M
Venterra engineer, build, and support the operations of wind energy developments around the world.
16
BBOXX
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.
17
Oxford PV
Funding: $152.2M
Oxford PV is the technology leader in the field of perovskite solar cells.
18
Aegis Energy
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.
19
Nyobolt
Funding: $113.6M
Nyobolt is a developer of high-powered battery technology used to serve automotive applications.
20
First Light Fusion
Funding: $107M
First Light Fusion (FLF) develops Inertial confinement fusion reactor that can produce power.
21
Fuse Energy
Funding: $100.7M
Fuse Energy offers commission-free energy; 10x cheaper; 10x better, and 100 per cent renewable energy.
22
Domna
Funding: £70M
Domna provides retrofit assessment software that predicts works programme, maximising energy efficiency services to housing properties.
23
EV Energy
Funding: $87.8M
Ev.energy is a smart charging software platform for electric vehicles to reduce carbon emissions and costs.
24
Origami Energy
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.
25
My Energi
Funding: £60M
My Energi makes Electric Vehicle charging equipment and eco-smart home devices.
26
Addionics
Funding: $73M
Addionics is creating next-generation batteries for electric cars through intelligent 3D battery architecture and engineering.
27
Iceotope
Funding: $73.3M
Engineered to cool the whole IT stack, in every use case, from Hyperscale to the Extreme Edge
28
Bramble Energy
Funding: $57.8M
Bramble Energy is an innovator energy technology company that designs and manufactures high-performance, low-cost, and fuel cell stack
29
Trojan Energy
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.
30
Moixa
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.
31
Exagen
Funding: £35M
Exagen Group is building the next generation of utility scale solar farms co-located with grid-balancing battery storage facilities.
32
Sunamp
Funding: $43.5M
Sunamp is a company that provides industrial and residential heat battery storage systems.
33
HiiROC
Funding: £26M
HiiROC is an industrial company that produces hydrogen from biomethane, flare gas, or natural gas with no CO2 emissions.
34
Breathe
Funding: $33M
Breathe Battery Technologies is a developer of electric vehicle battery charging control software for automotive manufacturers.
35
Orbital Marine Power
Funding: $31.9M
Scotrenewables Tidal Power is a renewable energy research and development company focused on tidal power.
36
Naked Energy
Funding: £24.4M
Naked Energy has developed an innovative hybrid solar technology generating combined heat and power.
37
Rovco
Funding: £24M
3D vision and artificial intelligence applied to subsea robotics servicing offshore wind decommissioning
38
QiO Technologies
Funding: £21.4M
QiO Technologies is an AI sustainability tech company that provides a sustainability suite to reduce greenhouse gas emissions.
39
Fuuse
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.
40
Modo Energy
Funding: £16.1M
Providing a data-driven energy platform, Modo Energy is emerging as one of the key players in optimising energy storage.
41
Piclo
Funding: £15.9M
Piclo develops software to make electricity grids smart, flexible and sustainable.
42
RheEnergise
Funding: £14M
RheEnergise is bringing innovation to pumped energy storage. We call our new solution High-Density Hydro
43
Cheesecake Energy
Funding: £14M
Cheesecake Energy is developing advanced thermal and compressed air energy systems to store energy.
44
Volteras
Funding: $17.5M
Volteras collects, standardizes, and optimizes data from hundreds of energy devices into a single data model.
45
Verv
Funding: $16.9M
Verv is an intelligent home hub, which gives the power to take control of energy usage to ultimately reduce energy bills.
46
Tem
Funding: $16.9M
Tem. develops and provides innovative solutions to manufacture renewable energy generators.
47
Continuum Industries
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.
48
AssetCool
Funding: £12.8M
AssetCool produces photonic coatings and materials that enhance the functionality of electrical networks.
49
Electron
Funding: £11M
Electron is a start-up harnessing blockchain technologies to design more efficient, resilient and flexible systems for the energy sector.
50
Mocean Energy
Funding: $14.4M
Mocean Energy develops new technologies which can harness the power of waves – and accelerate the transition to a zero-carbon world.
Editor: Alexander Gillet
Alexander Gillet is a senior editor for EnergyStartups. He has a deep background in energy sector and startups. Alexander graduated from Emlyon Business School, a leading French business school specialized in entrepreneurship. He has helped several non-profit organizations dedicated to promoting environmental education and sustainability and has written over 250 articles on energy technology for various websites. In his free time, Alexander enjoys yoga, camping and exploring the Blue Ridge Mountains. You can contact Alexander at alexgillet(at)energystartups(dot)com