Choosing a green business energy supplier can be difficult. Prices are usually hidden behind quotes, and it can be unclear just how green an energy supplier actually is.
We’ve compared leading green energy suppliers in the UK, delving into their fuel mix and customer service ratings, as well as any additional perks of signing up to a supplier and referral schemes where you and a friend, family member, neighbour or fellow business owner can earn a reward.
What is green energy?
Green energy is energy that can be produced without causing harm to the natural environment. Renewable energy comes from sources replenished by natural resources (such as the sun or wind).
Although green energy and renewable energy are often used interchangeably, it’s important to note that there is a slight distinction between the two.
Most green energy sources are considered renewable, but not all renewable energy sources are considered green. This is because if carbon emissions were associated with the construction of the infrastructure, an energy source cannot be considered green.
Why use green energy?
Aside from the environmental benefits, such as reducing your carbon footprint and mitigating climate change, green energy can lower bills in the long-run with renewable energy sources like solar panels.
Businesses can also become more energy efficient by using green energy, with smart meters allowing you to see how much energy you have used and cut back on surplus usage.
The UK government are actively encouraging small businesses to use green energy, offering various grants and incentives to make the switch. These include Carbon Trust Green Loans, the Smart Export Guarantee and the Energy Savings Opportunity Scheme.
Finally, using green energy can boost your brand reputation and win over new customers who are environmentally conscious.
However, businesses looking to make the switch to green energy should be aware of greenwashing and know how to spot it.
What is greenwashing?
Greenwashing is when energy suppliers present themselves as being sustainable and environmentally friendly whilst continuing to invest heavily in fossil fuels.
This leads customers to believe that they are helping the environment, when actually they are not having as positive an impact as they think they are.
Examples include Shell, who in 2023 had an advert banned by the Advertising Standards Agency which promoted its green initiatives because it did not include information that most of its business is based on environmentally-damaging fossil fuels.
In the energy industry, greenwashing is claiming to offer ‘100% renewable energy tariffs’ when actually the energy is sourced from ‘brown power’ – energy produced by burning polluted sources.
Energy suppliers can claim to be 100% renewable because of a loophole in regulations which allows them to buy REGOS (the certificate to show that energy is renewable) separately to the renewable power.
How to know if an energy supplier is actually green
- The company says it owns renewable generation, such as solar or wind farms.
- Examine their fuel mix disclosure.
- Look up their Clean Power Score on Matched Energy.
- Research if the company helps customers lower their carbon footprint – for instance, do they offer solar panel installation, heat pumps, or EV chargers?
Comparison table of UK green business energy suppliers’ Fuel Mix Disclosures (electricity)
| Renewables | Nuclear | Gas | Coal | Other | |
| UK average | 42.1% | 16.2% | 33.3% | 5.9% | 2.5% |
| Octopus | 86.4% | 13.6% | 0% | 0% | 0% |
| Ecotricity | 100% | 0% | 0% | 0% | 0% |
| 100Green | 100% | 0% | 0% | 0% | 0% |
| Good Energy | 100% | 0% | 0% | 0% | 0% |
| British Gas | 35% | 55% | 8% | 1% | 1% |
Comparison of UK green business energy suppliers
Octopus Energy
Alongside being the UK’s largest energy supplier, Octopus Energy are one of the greenest energy suppliers available to UK businesses.
Octopus Energy has invested over £6 billion into solar and wind farms, and aim to generate enough renewable electricity for 15 million homes across Europe by 2030.
As a business customer, you can sign your company up to Octopus Electric Vehicles and get a 5 star rated Electric Vehicle [EV] salary sacrifice scheme, meaning your employees can reduce their taxable income and receive a new EV while saving up to 40%. For SMEs, there are three specific plans:
- Shape Shifters – this is where you can choose one of two plans. With Shape Shifters: Trio, you get 21 hours of cheaper energy guaranteed. By using electricity outside of peak rate times (4pm – 7pm) you’ll cut your energy costs. With Shape Shifters: Agile, your prices change every half-hour, in line with wholesale energy costs. You’ll be able to see your prices a day in advance, meaning you can plan your energy usage accordingly.
- Multi-site business energy, for if your business needs to manage multiple sites’ energy in one portfolio.
- Business export tariffs, meaning you can earn money for the energy you send back to the grid.
Octopus Energy also have a referral scheme where if a fellow business switches to Octopus Energy using your link, you both receive £75.
Trustpilot rating: 4.8/5 (800,049 reviews)
Ecotricity
Ecotricity claims to be the world’s first green energy company and is linked to various UK green projects including Forest Green Rovers Football Club. They are a Which? Eco Provider for Energy and have been ISO 14001-certified since 2020.
Ecotricity ranked top in Citizens Advice comparison of energy supplier’s customer service (October – December 2025 ) with 3.93/5, with their billing and metering scoring 3.3/5.
They are one of the more expensive options on the market, although this can be partly explained by them being exempt from the price cap on default energy tariffs because they have proved to Ofgem that they have higher costs to support renewables, such as their Bills into Mills model, which reinvests your payments into new clean energy projects.
Ecotricity have a referral scheme where you and your friend, family member or neighbour can both receive £25 when they switch to Ecotricity.
Trustpilot rating: 4.2/5 (6,506 reviews)
100Green
100Green are a multi-award winning energy provider, recognised as the number 1 energy supplier by the Ethical Consumer and receiving 100/100 with the Good Shopping Guide for Ethical Business. Their dual-fuel tariffs have also been awarded Gold Standard by Uswitch.
100Green state that their electricity fuel mix is 100% renewable in contrast to the average UK electricity fuel mix (42.1%) and that their fuel impact has 0.000g per kWh for radioactive waste and 0.00g per kWh for CO2 emissions. They can also supply 100% renewable gas.
Notably, 100Green received the highest score in the Citizens Advice comparison of energy suppliers for call waiting time (4.8/5), with 98% of calls answered within 30 seconds.
However, 100Green also scored 0/5 for Customer Commitment on the Citizens Advice comparison of energy suppliers. This means that the company did not meet certain criteria, such as completing 98% of switches within 5 working days or improving their support for vulnerable customers.
Trustpilot rating: 4.6/5 (1,487 reviews)
Good Energy
Good Energy are another energy company exempt from the price cap on default energy tariffs because they have proved to Ofgem that they have higher costs to support renewables. This means that they are more expensive than other providers.
Good Energy provides hourly matching, which means you can align your energy use with renewable generation. This means you can make sure your energy is genuinely renewable and meet your ESG goals. Good Energy was ranked top in the Matched Clean Power Index with an 88% Clean Power Score. This score is the fraction of customer demand that is met by clean power, hour-to-hour.
It’s worth noting that Good Energy scored joint top for fewest complaints in the Citizens Advice comparison of energy suppliers (4/5), tying with Ecotricity.
Trustpilot rating: 4.8/5 (14,603 reviews)
British Gas
British Gas have made significant strides in becoming greener, with Centrica (who own British Gas) opening its first solar farm in Wiltshire in 2023. In the Matched Clean Power Index, British Gas Trading came second with 81% Clean Power Score. They are, however, heavily reliant on nuclear energy to deliver clean power, with 55% of their energy mix coming from nuclear, whereas renewables was only 16%.
If you take out a British Gas business contract, you can opt in to receive 100% Natural Renewable Electricity for the same price as their standard Zero Carbon electricity (not available to British Gas Lite customers).
The Natural Renewable Electricity product is verified as 100% renewable by the Carbon Trust, and comes from solar, wind and hydropower.
British Gas business customers also get a certificate to easily demonstrate their sustainability.
Trustpilot rating: 4.4/5 (339,739 reviews)
