Updated: 19 September 2025

Top 100 Green Energy Companies in the UK | 2025

Top 100 Green Energy Companies in the UK | 2025 More of us are seeking green energy options, and the movement now spans well beyond

Words Sarah Cheesman

More of us are seeking green energy options, and the movement now spans well beyond individuals. The UK’s renewable energy sector is evolving, with a rich mix of startups and scale-ups rising to the challenge of decarbonisation.

From offshore wind to innovative research into fusion power, the UK hosts a dynamic array of companies at the forefront of climate innovation.

In the past, we highlighted how purpose-driven businesses like these emerged as beacons during the COVID-19 pandemic. But while the pandemic temporarily reduced global fossil fuel use and CO₂ emissions, afterwards we saw a rapid rebound beyond pre-lockdown levels. The International Energy Agency now confirms that those declines were short-lived.

Since 2013, the number of active clean energy companies in the UK has grown, from just 6,345 up to 11,841 in 2024, reflecting the sector’s expansion in recent years.

Meanwhile, government strategy is reinforcing the trend. The 2025 Clean Energy Industries Sector Plan aims to double clean energy investment to over £30 billion per year by 2035, with £40 billion of private investment already announced.

Explore the UK’s Sustainable Companies

From renewable energy to sustainable fintech, check out the latest insights and trends in the UK’s sustainability economy.

What is green energy?

Green energy refers to clean or renewable energy sources that produce minimal or no pollution or greenhouse gases, making them environmentally friendly.

The alternative is fossil fuel like coal, oil, and natural gas, which release carbon dioxide and other harmful pollutants when burned. Clean energy sources have a much lower impact on the environment.

For the purpose of this article, we are only including companies identified as ‘renewable energy’ on the Beauhurst platform. This means that cleantechs are excluded and covered in a separate article.

Why is green energy important?

Green energy is crucial for a number of reasons. Environmentally, it helps combat climate change and reduce air pollution by emitting little to no greenhouse gases, protecting ecosystems, and improving public health.

From a sustainability perspective, clean energy relies on renewable resources, offering a more stable and secure energy supply for the future, unlike finite fossil fuels.

Economically, the growing clean energy sector generates jobs and drives growth, especially in regions where traditional energy industries aren’t possible. The shift to clean energy is often accompanied by government incentives and policies such as the Biden administration’s Inflation Reduction Act of 2022 in the United States.

These policies encourage further development in this area and are designed to create a more favourable business environment for clean energy, attracting both domestic and foreign investments.

Health-wise, clean energy improves air quality, potentially reducing respiratory and lung diseases. Additionally, the costs of renewable energy sources have become increasingly competitive with traditional fossil fuels, often being the most cost-effective choice for new electricity.

Global investment in green energy

The need for green technology is clear and, thankfully, we’re not the only ones who think so. According to the IEA, global energy investment is on track to reach $3.3 trillion in 2025, with approximately $2.2 trillion directed toward clean energy sources; nearly double what’s going into fossil fuels.

BloombergNEF adds that renewable energy investment reached a record $386 billion in the first half of 2025, driven by rapid growth in small-scale solar and offshore wind.

Innovation in energy storage is rising fast. In 2025, the world expects 222 GWh of new storage capacity, a 26.5% year-on-year surge, with emerging technologies such as hydrogen and liquid-air storage supporting enhanced flexibility. UK-based Highview Power, for instance, raised £300 million to build a pioneering 50 MW / 300 MWh liquid-air energy storage facility in Manchester, set to begin operations in early 2026.

In 2024, the world installed 582 GW of new renewable energy capacity; a 19.8% increase over the previous year. Solar PV accounted for 78%, with total global capacity reaching 4,443 GW, led by China and other Asian nations.

UK green energy sector: headline figures

We currently track almost 16,000 green energy companies in the UK, and whilst these innovators are spread across the country, they’re especially concentrated in London (3,268), the South East (1,696), and the South West (1,489).

Meanwhile, Scotland, which has a strong offshore wind industry, is home to 1,094 clean energy companies.

Green energy companies’ stages of evolution

High-growth UK clean energy companies are relatively early-stage, with 31% classed as Seed stage and 24% as Venture. 27% are considered to be at the Established stage, and 11% are currently at the Growth stage.

These numbers reflect the context that the sector is in a comparatively nascent stage to more established industries, following a rapid increase in green energy startups over only the last decade.

Green energy investment trends

In 2015, just a decade ago, renewable energy companies raised £437m in investment across the entire year. Contrast this with 2024, which saw 252 deals completed, totalling £1.27b.

And in 2025 so far, £1.29b has been raised in renewable energy companies.

Enter ESG signals

Which companies are ESG signals useful for?

While our ESG signals are useful for any business interested in companies with strong ESG credentials, they are particularly beneficial for local governments or councils searching for greener energy solutions for their region. We support councils with access to easy, searchable data so they can find exactly what they need, such as Lancashire County Council.

Many of us also prefer to work with people who share our ideals, and this is why ESG data is essential for investors. Companies such as Puma Private Equity use Beauhurst to help them make important decisions without hours of research. Combining all our company and ESG data, Beauhurst offers you the most comprehensive dataset out there.

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The UK’s top green energy companies

We’ve ranked seed, venture, growth and established-stage private companies by the amount of equity they have raised to date.

The data is accurate as of 19th September 2025.

These businesses are all headquartered in the UK and have hit our Clean & Renewable Energy ESG signals.

Renewable Power Capital is a pan-European investment platform, founded in 2020 and headquartered in London, with backing from CPP Investments.

The company focuses on developing, constructing, and owning solar, onshore wind, and battery storage projects, helping to accelerate Europe’s energy transition while delivering stable, long-term returns.

Since its launch, Renewable Power Capital has raised significant capital across multiple stages. In 2022, it secured £68.4m at seed stage for a 56% stake, followed by £87.8m at venture stage in 2023 for a 38% stake.

Most recently, in September 2024, it raised £23.4m at growth stage for a 10% stake.

Venterra Group aims to accelerate the global energy transition through offshore wind power.

Founded to address the fragmented wind services market, the company is acquiring and integrating specialist firms, adding management expertise and capital to help them scale.

Since its inception, Venterra has raised substantial investment to fuel its growth and fund its acquisitions. This includes £37.4m at seed stage in 2021, £51.5m at venture stage in 2022, and £100m at growth stage in 2023 with backing from First Reserve, BeyondNetZero and other investors.

Most recently, in October 2024, it secured a further £29.8m at growth stage. Venterra has used this funding for six acquisitions, strengthening Venterra’s expertise across engineering, construction support and consultancy services.

Tokamak Energy is pioneering the development of commercial fusion power — aiming to make clean, secure and affordable energy a reality by the 2030s.

Founded in 2009 as a spin-off from the UK Atomic Energy Authority, the Oxfordshire-based company has over a decade of experience in spherical tokamak technology and high-temperature superconducting (HTS) magnets.

Tokamak Energy has secured 11 equity fundraisings and 13 grants to date. Major backers include British Patient Capital (Future Fund: Breakthrough), Legal & General Capital, BW Group and Furukawa Electric.

Its most recent round in December 2023 raised £94.9m at growth stage for a 33% stake, following earlier raises of £67.1m in 2020 and £19.2m in 2018. In addition, the company continues to attract government support, with recent grants from Innovate UK and the US Department of Energy, underscoring its global significance in the race for fusion energy.

Field develops battery energy storage systems (BESS). By storing renewable power and releasing it back to the grid when demand peaks, Field is helping create a greener, more flexible and more reliable energy system.

In 2021, Field secured £5.7m at seed stage from Giant Ventures and business angels, followed by £32.4m at venture stage in 2022 with support from LocalGlobe and Plural.

A £200m venture round in 2023, led by DIF Infrastructure, enabled the business to scale rapidly, and in 2025 it announced a £42m loan facility from ING Bank and Rabobank to further expand its battery portfolio.

Fidra Energy develops and operates large-scale energy storage projects, supporting the transition to clean and renewable power.

In September 2025, the Edinburgh-based company raised £445m in equity investment from EIG Partners and the UK’s National Wealth Fund, marking its first fundraising round. This raise will support its Thorpe Marsh Battery Energy Storage System project in Doncaster and other projects including a site in Nottinghamshire

OVO Group is one of the UK’s largest energy companies, powering homes and businesses with a focus on clean, affordable energy.

Founded in 2009, OVO has attracted strong investor support over the years. Most recently, in July 2023, OVO secured another £200m from Mayfair Equity Partners and Morgan Stanley Investment Management to fuel further growth.

Alongside investment, OVO has been an active acquirer in the sector. Notably, it acquired SSE’s retail arm for £500m in 2020, significantly expanding its customer base, as well as CORGI HomePlan, VCharge and, most recently, EV charging app Bonnet in 2023.

The company has also received support through seven grants, including funding from Innovate UK and the Sky Zero Footprint Fund, to advance low-carbon heating, energy flexibility and innovation projects.

ITM Power is a global leader in hydrogen energy solutions, specialising in the manufacture of integrated hydrogen energy systems for clean fuel production and storage.

Founded in 2001 and floated on AIM in 2004, the first UK-based fuel cell company to go public, ITM Power has grown into a key player in the energy transition. The company is headquartered in Sheffield, with additional offices in Germany, France, the USA and Canada.

In 2019, the company raised £61.1m at growth stage in a round led by Linde, followed by £172m in 2020 with backing from Snam and other investors. Its largest raise to date came in 2021, when ITM secured £250m, supported by BofA Securities and Investec.

In addition to equity backing, ITM Power has benefited from extensive grant funding — 39 awards in total, including support from Innovate UK and the UK energy sector to accelerate hydrogen innovation. In 2021, the company also spun out Motive Fuels. In 2025, it was listed on the FT1000 as one of Europe’s fastest-growing companies.

GRIDSERVE is a sustainable energy supplier and its GRIDSERVE Electric Highway, featuring Electric Forecourts® and Electric Hubs aims to make zero-carbon transport more accessible than ever. Alongside charging, the company also operates an EV leasing business, helping individuals and organisations accelerate their transition to clean mobility.

The company has attracted substantial investment to support its growth. Early backing included £16.7m in 2021 from Novuna, followed by a huge £346m equity raise in 2022, led by Infracapital.

In 2023, GRIDSERVE secured a £300m loan facility with support from lenders including NatWest, Lloyds, Santander, and the UK’s National Wealth Fund. Most recently, in March 2025, the business raised £55.8m from Infracapital, Mitsubishi HC Capital UK and TPG to expand its sustainable energy infrastructure further.

In parallel, GRIDSERVE has benefitted from multiple Innovate UK grants, including a £5.1m award in 2019 and a record £33.5m grant in 2023, supporting its solar, storage and EV charging projects.

Zenobē is one of the UK’s leading providers of battery storage and electric vehicle charging infrastructure, helping to deliver clean power and sustainable transport solutions through the use of large-scale batteries. Its projects support both the decarbonisation of the grid and the rapid shift to electrified transport.

The company has attracted major backing to scale its operations. Early investment included £37.6m at seed stage in 2017 from Tiger Infrastructure Partners, followed by venture-stage rounds with JERA, TEPCO and Infracapital.

In December 2023, Zenobē completed a £476m growth-stage fundraising, with investment from KKR and Infracapital — one of the largest private capital injections into the UK’s energy transition sector to date.

Its growth has been recognised across multiple high-growth lists, including HolonIQ’s Europe Climate Tech 2023, Sifted 100: UK and Ireland 2024, BusinessCloud FactoryTech 50 2024, and The Sunday Times Tech 100 2025.

Part of the wider Octopus Group, Octopus Energy is one of the UK’s largest energy transition companies, aiming to deliver affordable, sustainable power while reshaping the global energy system.

The company has secured significant investor support as it scales internationally. Key fundraisings include £182m in 2020 from Origin Energy and Tokyo Gas, £636m in 2021 from CPP Investments, Generation Investment Management and others, and most recently, £631m in December 2023.

Alongside equity investment, Octopus has received government and Innovate UK grants, including a £2.8m award in 2018 to advance clean energy innovation. The business has also pursued an ambitious acquisition strategy, completing more than 20 deals worldwide.

Recent acquisitions include UK-based Exagen Group, German firm Kwest, Dutch EV smart charging company Jedlix, and Energetiq in Australia, extending its reach across Europe and beyond.

Recognised as a high-growth leader, Octopus Energy has appeared on the E2E Job Creation 100 (2023), the Lazard T100 European Venture Growth Index (2024), and BusinessCloud’s EnviroTech 50 (2024).

The future of green energy companies in the UK

In 2024, the net zero sector grew by 10.1%, contributing £28.8 billion to the economy and supporting nearly one million jobs, with wages significantly above the national average.

In 2025, new government policies further support the sector. The Clean Energy Industries Sector Plan aims to “build it in Britain,” pairing £700 million in supply-chain investment with a mandate to double clean energy investment to £30 billion annually by 2035.

Alongside this, the establishment of Great British Energy, a public energy company formed under the Great British Energy Act 2025, signals a strategic push to embed renewable generation at the heart of the nation’s energy system.

On the market front, reforms to the Contracts for Difference scheme, including extended contract lengths and a £544m Clean Industry Bonus, are attracting investor interest with the goal of keeping the UK’s offshore wind targets on track.

Energy security is being shored up with nuclear extensions and flagship projects. Heysham 1 and Hartlepool plants will remain operational until 2028, delivering an estimated 12 TWh to the grid. And Sizewell C has moved forward with £14.2 billion in government funding, promising enough power for six million homes and 10,000 jobs.

Despite these advances, challenges persist. Policy uncertainty and fears over contract stability could deter investment and slow progress. There’s also concern over a skills exodus, with many sector specialists leaving the UK amid stagnating renewable projects and high taxation.

Nevertheless, with strong growth, public and private investment, and sector-wide momentum, the UK remains well-positioned to lead the green energy transition in the years ahead.

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