London is emerging as an important market for clean energy with a growing interest in hydrogen as a solution for cutting emissions from transport, industry, logistics and energy intensive operations. Green hydrogen, which is made from renewable electricity instead of fossil fuels, is attracting particular attention among the different types of hydrogen.
For businesses looking to identify the best green hydrogen production companies in London, it is important to look beyond the companies that simply produce hydrogen. The sector includes project developers, providers of electrolyser technology, energy companies, storage specialists and organisations developing complete hydrogen supply chains.
This guide looks at some of the major companies and projects involved in green hydrogen production in London and the wider UK market.
What’s green hydrogen?
Green hydrogen is created by splitting water into hydrogen and oxygen with an electrolyze. If the electricity used in the process comes from renewable sources like wind or solar, the resulting hydrogen can have very low associated carbon emissions.
Green hydrogen will be particularly useful in sectors which are hard to electrify directly. Possible applications include:
•Buses and heavy transport
• Heating in industry
• Production
• Chemicals manufacturing
• Power backup
• Storage of energy
• Fuels for shipping and aviation
• Proportion of renewable energy
The UK government is supporting the development of electrolytic hydrogen projects thru schemes like the Hydrogen Allocation Rounds. Its HAR2 shortlist lists projects across the country, including Harper Lane Hydrogen in Greater London, led by Hygiene Energy Holdings.
Leading Green Hydrogen Companies and Projects in London
1. Hygen Energy
Hygen is one of the companies worth watching when researching green hydrogen production companies in London. The company develops hydrogen production projects and works across applications including transport, industry, power, grid injection, and ammonia.
Hygen is particularly relevant to London because its hydrogen strategy includes supplying hydrogen to transport applications. The company says it is working with partners to deliver hydrogen solutions for bus operators in cities including London.
Hygen is also involved in the Harper Lane Hydrogen project, which appears on the UK government’s HAR2 shortlist for Greater London. This makes the company an important name in the region’s developing green hydrogen ecosystem.
Top Green Hydrogen Companies and Projects London:
1. Hygen Energy
Hygen is one of the green hydrogen production companies in London to watch out for when doing your research. The company is working on hydrogen production projects and operates in sectors such as transport, industry, energy, grid injection and ammonia.
Hygen is particularly relevant to London because its hydrogen strategy is to include supplying hydrogen to transport uses. The company said it is working with partners to offer hydrogen solutions for bus operators in cities including London.
Hygen is also involved in the Harper Lane Hydrogen project, which is on the UK Government’s HAR2 shortlist for Greater London. This makes the company a key name in the emerging green hydrogen ecosystem in the region.
2. ITM Power
ITM Power is a leading electrolyser technology company in the UK, based in Sheffield. ITM is not just a hydrogen producer, it is very much about the technology for making green hydrogen by electrolysis.
The company is developing PEM electrolyser systems that can be integrated into large-scale hydrogen production plants. ITM has also collaborated with UK hydrogen developers, such as Hygen and Protium.
In 2026, ITM Power and Protium announced a strategic partnership to develop, invest and operate industrial-scale green hydrogen production plants across the UK.
The significance of ITM’s role is that the growth of London’s hydrogen economy will need dependable and scalable electrolyser technology, as well as renewable electricity and hydrogen infrastructure.
3. Protium Green Solution
Protium is a UK-based green hydrogen energy company developing renewable hydrogen projects. Its business model combines renewable power generation with hydrogen production and the associated infrastructure.
Across the UK, the company has developed projects and teamed up with technology providers such as ITM Power. Protium and ITM partnership 2026 to support the development and operation of industrial scale hydrogen facilities.
Although Protium’s current project portfolio is not confined to London, its integrated approach makes it a company to watch as the UK’s hydrogen production network expands.
4. Carlton Power
Carlton Power is a UK-based energy infrastructure developer with a portfolio of green hydrogen projects across the UK. Its portfolio shows how large-scale renewable hydrogen plants can be linked to industrial customers.”
For example, its Trafford Green Hydrogen project in Greater Manchester aims to produce hydrogen for industry, transport and heating using renewable energy. The project has a final installed capacity of 200 MW with an initial phase of 20 MW.
Carlton Power has also set up a joint venture with Schroders Greencoat, the Green Hydrogen Energy Company, with the aim of a significant green hydrogen project portfolio in the UK.
Carlton Power’s largest projects are outside London but it is relevant to the wider UK hydrogen market as companies developing the national supply chain can eventually support demand in London and other large urban centers.
5. HYRO Energi
HYRO Energy is another company involved in the growing green hydrogen scene around London. It will be sited at Kimberly-Clark’s manufacturing facility in Gravesend, Kent, for its Northfleet Green Hydrogen project.
The project concerns the production of green hydrogen via electrolysis and its direct supply to an industrial customer. Detailed design, procurement and enabling works are underway with construction to commence in April 2026, the project website states.
Its Kent location makes it especially relevant to the wider London and South East hydrogen economy with industrial users able to benefit from locally produced hydrogen
Why green hydrogen is needed in London
London has ambitious decarbonisation requirements, but not all applications can be easily converted to battery-electric or conventional renewable electricity.
Hydrogen could complement electrification in sectors including heavy duty transport, industrial processes and long duration energy storage.
One of the biggest advantages of producing hydrogen closer to where it is used is that it could reduce the need for transport. Local production can also help create hydrogen hubs that integrate production, storage, distribution and consumption.
Green hydrogen, however, remains an emerging industry. The economics of production are very sensitive to the prices of renewable electricity, electrolyser costs, utilisation and infrastructure. Research into UK green hydrogen projects has revealed that electricity cost is one of the most important factors impacting the levelised cost of hydrogen.
How to Select a Green Hydrogen Production Firm
When companies are looking at hydrogen suppliers or project partners there are a few things they should look at:
Production technology: Ensure the company is using proven electrolyser technology and that the system can be scaled with future demand.
Renewable electricity The green hydrogen’s environmental benefits are heavily reliant on the source of electricity used for electrolysis.
Production capacity: Examine the current capacity and the company’s plans to expand it.
Storage and distribution Making hydrogen is only one part of the supply chain. Storage, compression, transportation and dispensing are all equally important.
Project maturity: Differentiate between operational facilities, projects under construction, funded projects and early stage proposals.
End use capability: Companies with experience in supplying hydrogen to transport or industrial customers may be better placed to offer more practical solutions for commercial users.
The London Green Hydrogen Future: The London hydrogen market is expected to evolve alongside the wider UK hydrogen economy. The speed at which they are deployed will depend on government funding, private investment, development of renewable power and better electrolyzed technology.
This nascent market already includes the Greater London and South East regions, as evidenced by projects such as Harper Lane and North fleet. At the same time, national developers and technology firms are building the infrastructure and expertise needed to make green hydrogen commercially viable.
In the future, interconnected hydrogen hubs may be established where renewable electricity, electrolysis, storage, pipelines and end users are integrated.
It could create new opportunities for London businesses to cut carbon emissions, while improving energy resilience and supporting the transition to a low carbon economy.
Final thoughts
When looking for the best green hydrogen production companies in London, how much hydrogen they produce today should not be the only thing to judge them by. The industry is still growing with many key projects in planning, funding, construction or investment phases.
Companies like Hygen Energy, ITM Power, Protium, Carlton Power and HYRO Energy are all helping to build different parts of the emerging hydrogen ecosystem, from project development and production to electrolysis technology and industrial applications.
As the investment in renewable hydrogen infrastructure expands, London and the wider South East could become significant demand and distribution hubs for the UK’s clean hydrogen economy.
Businesses interested in green hydrogen should therefore assess not only production capacity but also technology, renewable power sourcing, project maturity, storage, distribution and long-term supply capability.
Frequently Asked Questions?
1. Top green hydrogen production companies in London
A. Hygen Energy is a key player in the development of green hydrogen in Greater London, including the Harper Lane Hydrogen project. Other companies of interest to the wider London and UK market include ITM Power, Protium and HYRO Energy.
2. Is green hydrogen produced in London?
A. London’s green hydrogen sector is still developing with a number of projects in different phases. The UK government’s HAR2 shortlist includes the Harper Lane Hydrogen project in Greater London, with other projects such as Northfleet, nearby, moving to construction.
3. What is green hydrogen for?
A. Green hydrogen can be used in industrial processes, heavy transport, energy storage, backup power, chemical production and other applications that are difficult to electrify directly.
4. Production of green hydrogen
A. Green hydrogen is usually made using electrolysis. An electrolyser uses electricity to break water down into hydrogen and oxygen. The hydrogen produced with renewable electricity is called green hydrogen.
5. What’s the future for green hydrogen in London?
A. The future will be driven by project investment, availability of renewable electricity, hydrogen infrastructure and commercial demand. London’s transport and industrial ecosystem is large enough to make it a major hub for demand for hydrogen as production capacity grows across the UK.