Top 10 Green Energy Companies

Top 10 Green Energy Companies in the UK | 2024

John McCrea,
 Updated: 17 April 2024

More and more of us are searching for green energy options—and this goes beyond the individual. The high-growth cleantech and renewable energy sectors are now seeing a diverse ecosystem of startups and scaleups working to protect our planet.

From electric vehicles (EVs) and renewable energy companies to insect-based protein for your pets, the UK is home to a whole host of exciting companies developing innovative clean technologies to mitigate climate change. And in our annual equity market update, we stressed the need for purpose-driven businesses like these during the coronavirus pandemic.

Whilst the arrival of COVID-19 did temporarily reduce global fossil fuel consumption and CO2 emissions, we’ve already seen these aggressively bounce back to—and now surpass—pre-lockdown levels. In fact, data from the International Energy Agency shows that global carbon emissions were 2% higher in December 2020 than in the same month in 2019, and grew by 1.1% in 2023. This has seen global CO2 emissions reach a new record high of 37.4 billion tonnes (Gt).

Since 2013, we’ve also witnessed the number of active clean energy companies rise from 48 to 243. And with the decarbonising transport promise from the UK government, we’re likely to see this number continue to grow. Here at Beauhurst, we thought now is a good time to look at the top clean energy companies in the UK, and what those companies are doing.

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.

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 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—this means it could last forever (in theory).

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.

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. Aquion Energy, Malta (Google X), and Highview Power are developing unique long-term storage solutions for the power generated by renewable energy sources.

The launch of the Circular Electronics Partnership (CEP) also saw Microsoft, Dell, Amazon, and Google join forces to help build a circular economy for electronics by 2030. Meanwhile, in Glasgow (home of COP26), Costa is trialling the use of blockchain technology to make it easier for its customers to caffeinate responsibly.

However, it’s not just big firms getting involved in the green revolution. Investors are also putting their weight behind the movement, with increasing numbers of Silicon Valley VCs now racing to back clean energy ventures. Similar trends are being seen outside of San Francisco, too.

Learn more about how Greenaway Scott uses Beauhurst to target some of the most ambitious companies in the UK.

UK green energy sector: headline figures

Of the 4.6m private UK companies, there are now over 17,000 operating in the greentech and clean energy space.

The UK’s cleantech innovators are spread across the country, but are especially concentrated in London (5,984), the South East (1,912), and Scotland (1748).

Meanwhile, Scotland, which has a strong offshore wind industry is home to 1,666 clean energy companies.

Green energy companies’ stages of evolution

High-growth UK clean energy companies are relatively early-stage, with 47% classed as Seed and 34% as Venture, within Beauhurst’s ‘stage of evolution’ framework. In comparison, just 9% are currently at the Growth stage and 6% at Established stage, whilst 5% are inactive (albeit not ‘dead’) or in administration/liquidation, the Zombie 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

Between 2013 and 2023, announced equity investment into high-growth cleantech companies saw significant growth, in both number and value. In fact, just 200 deals were secured by green energy startups in 2013, amounting to £605m. But by 2023, yearly deal numbers had risen to 548, amounting to a huge £2.7b.

By the end of Q1 2024, 132 deals with UK green energy companies have already been announced. And whilst the amount raised this year (£408m) is unlikely to reach the heights seen in 2021 of just under £9b raised, it’s still a positive step in the right direction.

Investors have been particularly active in the UK’s cleantech innovation space since 2013, with crowdfunding platforms Crowdcube and Seedrs facilitating 137 and 97 announced equity deals respectively. Green Angel Syndicate (managed by Green Angel Ventures) came in third with 38 deals, followed by Scottish Enterprise with 29 and Scottish Venture Fund with 26.

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.

Track the green economy

Identify, monitor and capitalise on opportunities with our market-leading Environmental, Social and Governance (ESG) data. We collect data on ESG for all companies across the UK—so you can find the all insights you’re looking for, in one place.


We used a unique methodology to select our top 10 green energy companies.

We’ve ranked seed, venture, growth or established-stage private companies by the amount of equity raised since the beginning of 2023. The data is accurate up until 11 November 2023.

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

Top clean energy generation companies

Which of the UK’s sustainability startups should you be looking out for next?

From solar energy to EVs (electric vehicles), our data team has compiled the top 10 green energy companies operating in the UK’s private market.



Date founded: 2013
Location: East of England

Tevva specialises in manufacturing Electric Range Extended Vehicles (EREVs), designed specifically for the urban delivery sector. The company has secured eight fundraisings, totalling £111m. As well as, 11 grants—for £10.8m. It also attended two accelerators: ELITE in 2016 and the Mayor’s International Business Programme.



Date founded: 2020
Location: Manchester

Iduna develops sustainable infrastructure, including a network of electric vehicle charging points. They have secured £118m through three rounds of equity fundraising to date. The highest and most recent of these was in October 2022, seeing them raise £110m through Octopus Energy. This was to support the expansion of its electric vehicle charging network by installing 1000 new charging points by 2024.

This transaction marked Octopus’ first stake in EV charging infrastructure, and provided a significant cash injection for Be.EV.


Oxford Photovoltaics

Date founded: 2010
Location: Kidlington

Oxford Photovoltaics develops solid-state dye-sensitised solar cells (perovskite cells) that can be printed on glass, such as building windows. To date, they have raised a total of £119m through 13 different funding rounds, including £34.1m in July 2019 and £10.7m in October 2022.

They have also received 12 grants to the value of £2.83m. The most recent of these was for £69.9k through Innovate UK to fund quantum computing for materials modelling applications in photovoltaics.


Tokamak Energy

Date founded: 2016
Location: London

Tokamak Energy was spun out of the Culham Centre for Fusion Energy (CCFE) in Oxford. It’s working to advance the development of clean energy production through fusion (the joining together of hydrogen atoms), using devices that combine plasma in a magnetic field along with superconductors.

To date, Tokamak Energy has secured £123m in equity fundraisings, across 10 rounds, and at least £11.4m in innovation grants. The green energy company’s January 2020 raise, totalling £67m, is being used to accelerate its plans to build a fusion reactor by 2030.


Flexion Energy

Date founded: 2020
Location: London

Flexion Energy aims to develop, build, own and manage energy storage systems, helping bridge the gap between the development and financing of energy storage sites. With a £150m investment from GLIL Infrastructure in July 2021, their aim was to construct and make operational an established pipeline of up to 300 MW of grid-connected battery storage systems over the following 24 months.

The deal was the 11th investment by GLIL, the £2.5bn infrastructure fund backed by Local Pensions Partnership and Northern LGPS.



Date founded: 2010
Location: London

BBOXX sells and installs off-grid solar panel systems to communities in countries with unreliable electricity supplies. They have raised £193m through a significant 14 rounds of equity fundraisings. In May 2023, they raised £53.9m through undisclosed investors, their largest fundraising to date.

Through a loan investment from SBM Bank in January 2022, they were able to finance a project to supply 470k Kenyans with solar equipment such as solar home systems and solar-powered appliances over the following two years.



Date founded: 2017
Location: Iver

GRIDSERVE develops sustainable energy technology for solar storage, with applications such as charging points for electric vehicles, and also provides an electric vehicle leasing service. To date, they have raised £210m in equity and loan fundraising, as well as £5.52m in grants. Their most recent round of equity fundraising was in August 2022, seeing £200m invested from Infracapital.

This funding was to expand its car leasing division, support the development of its sun-to-wheel model and deliver over 5,000 high-power chargers across its charging network by 2025.



Date founded: 2020
Location: London

Field, also trading as Virmati Energy, aims to build renewable energy infrastructure with a focus on energy storage. They have raised £240m through equity fundraisings to date, the most recent of which was completed in July 2023 for a huge £200m. This was invested into by DIF Infrastructure VII, with the aim of investing in its battery energy storage projects.

The investment will enable Field to accelerate the development and buildout of its 4.5 GWh pipeline of grid-scale battery energy storage projects in the UK and Western Europe as it seeks to contribute to the renewable energy infrastructure needed to reach net zero.


OVO Group

Date founded: 2009
Location: Bristol

OVO Group comprises a number of clean energy companies, including OVO Energy, which supplies gas and electricity. The company has seen a total of £259m raised through four funding rounds so far, the most recent being in February 2019 for £200m (verified at £109m). They have also received £250k in grant funding to help them with activities such as a zero carbon heating trial that will install emissions-reducing technology into 250 homes.

OVO Group has also made four acquisitions, namely Bonnet in November 2023, SSE in January 2020, CORGI HomePlan in May 2017 and VCharge in February 2017.



Date founded: 2012
Location: London

Sonnedix operates a range of global renewable energy projects. They have over 400 solar PV plants/farms across 10 different countries, and is the sixth largest PV portfolio in Europe. To date, they have raised £284m in equity fundraising over four rounds. The most recent of these was for £34.4m in June 2023, however their largest round of fundraising was in November 2022 for £128m.

In the same month, they partnered with Palantir Technologies Inc., a leading builder of operating systems for modern enterprises, to support their data transformation and capitalise on their vast renewables infrastructure. The multi-million-dollar partnership is contracted for four years.

The future of green energy companies in the UK

The future of green energy companies in the UK appears promising as the nation continues to prioritise sustainability and environmental responsibility. With an increasing awareness of the urgent need to combat climate change, the demand for clean and renewable energy sources is on the rise. Green energy companies are poised to play a pivotal role in this transition, driving innovation in technologies such as wind, solar, and tidal power. The UK government’s commitment to achieving net-zero carbon emissions by 2050 further incentivises the growth of these companies through supportive policies and financial incentives.

As the renewable energy sector matures, we can anticipate advancements in energy storage, grid integration, and efficiency, contributing to a more resilient and sustainable energy infrastructure. Collaboration between public and private sectors, along with international partnerships, will likely be key in realising the full potential of green energy, positioning the UK as a global leader in the transition to a low-carbon future.

Do you want to find out more about the fastest-growing green energy and cleantech companies in the UK? Beauhurst can help. Our comprehensive data platform gives you all the information you need about key players in this sector. With 5m+ profiles of active UK companies in one searchable system, we provide up-to-date visibility on every different industry and sector. We use a unique blend of machine learning models, data extraction tools and 60+ data analysts to provide our users with accurate, verified, and relevant data. Want more information? Speak to a member of our team today or book a demo to see us in action.

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