Installer Directory

The Best UK Green Energy Suppliers in 2021 And How To Choose One

The Best UK Green Energy Suppliers in 2021 And How To Choose One


It has become ever more apparent in the last decade that climate change and its side effects are the most pressing challenges that mankind is facing. Fortunately, there is a way we can prevent disaster and that is to reduce greenhouse emissions.

Back in 2019 The Department for Business, Energy and Industrial Strategy revealed that 85% of people in the UK supported the use of renewable energy. However, for many people, installing renewable energy into their home can still be too expensive despite government initiatives such as the Renewable Heat Incentive (RHI) and the Green Homes Grant. If you want to reduce your carbon footprint but are not yet in a position to install renewable energy the next best thing is to switch your energy supplier to one with green credentials. There has never been an easier time to switch to a green energy supplier. The industry is growing at such an incredible rate that there is more choice than ever before as the market moves towards embracing renewable energy.

It isn’t difficult to find a supplier that can provide 100% green electricity these days. In fact, most of the Big Six energy companies, British Gas, EDF Energy, E.ON, Npower, Scottish Power, and SSE have tariffs that offer this. You will have to turn your attention to the smaller energy suppliers if you want green gas too or at least a share of it.


Compare prices from local companies fast & free

Enter your postcode to compare quotes from leading professionals. We promise to keep your information Safe & Secure. Privacy Policy

What Is Green Energy

Green energy is electricity and gas that is generated from renewable sources instead of fossil fuels like coal and gas. It is renewable because it is collected from sources, such as wind and the sun’s rays, which are naturally replenishing. If you burn coal, you’re left with nothing but ashes and carbon dioxide.

The main renewables used are wind power (on-shore and off-shore), solar power, wave and tidal, biomass, hydroelectric and geothermal. Though nuclear power doesn’t produce carbon dioxide and is considered by some as a green, low carbon alternative to fossil fuels, it does produce nuclear waste which means it is not generally classed as ‘green’.

'Green gas' refers to Biomethane, which is a naturally occurring gas produced from the breakdown of organic materials and landfill gas and there is also syngas made from biofuels. 

How To Choose The Best Green Energy Supplier For You

Green energy doesn’t have to cost you more. If you use a price comparison website, you will find some green energy suppliers that offer cheaper tariffs and some that are more expensive. The price difference is usually down to just how green the energy really is. On the whole, you will pay more for a supplier that generates its own electricity from renewable sources and provides some level of green gas than you will if the supplier simply matches your usage by buying green energy.

Buying your energy from a green energy supplier does not mean that you will get all your energy from renewable sources. The National Grid electricity network links all power stations which means that your electricity will come from that pooled network.

To decide which green energy supplier is right for you, check their fuel mix and see if they can guarantee that you’re getting green electricity or if they are actually just offsetting your usage. It is possible to find out what type of energy your supplier uses as each year energy companies must report to Ofgem exactly how their energy is generated. This allows you to see which suppliers are truly green and which are still relying on coal for example.

If you want your energy supplier to provide some green gas you will need to check that they are a member of the Green Gas Certification Scheme. The green gas you receive will also be mixed with normal ‘natural’ gas. The UK does not produce enough green gas to supply all those who want it, but most companies offer carbon offsetting as an alternative to green gas.

You may be anxious about the stability of the smaller suppliers fearing that they will be less reliable, but it’s worth knowing that even if your provider goes bust, you’ll just be moved to a different supplier. According to customer satisfaction polls many of the smaller suppliers have better service and happier customers. Some of them such as Bulb and Octopus have become as well-known as the Big Six suppliers.

There are approximately 355 green energy tariffs currently on sale in the UK but it’s not like for like and often what is on offer is misleading.

Many supposed renewable energy suppliers are actually dependent upon a certification system from Ofgem called ‘Renewable Energy Guarantee of Origin’ (REGO) certificates. These REGOs are sold alongside the energy itself per MWh (Megawatt hours) to the energy supplier, allowing them to prove their energy is green. The more green energy a company generates, the more REGOs they can earn. However, a loophole currently exists that enables suppliers to buy REGOs without the energy. They can buy fossil fuel energy and provided they match the amount of REGOs per MWh they can still call themselves green. The term to describe this is greenwashing. These so called light green energy suppliers can buy themselves an ‘eco status’ without investing in renewables. Ofgem are looking at what measures they can bring in to stop this happening. In the meantime, if the deal you’re considering appears to be offering seriously cheap energy then it may be that your saving is costing the planet elsewhere.

Here are 5 the best renewable energy providers who are specifically offering 100% renewable energy and at least 10% green gas (biogas) making them the most sustainable on the market.  Many offer their energy tariffs at competitive rates with fixed rate options so that even if they are not the cheapest energy supplier, you can still expect your energy bills to come down.

Green Energy UK

Green Energy UK is the only supplier to offer 100% green gas as well as green electricity, making them the truly sustainable choice. Their renewable sources are hydro, solar and wind. Unlike other green energy suppliers, who offset their gas emissions Green Energy UK produces all of the gas it provides to customers from anaerobic digestion. You’ll have to pay more for these green credentials than you would with the ‘big six’ energy companies though, because Green Energy UK is exempt from the Ofgem price cap. However, Trust Pilot ranks Green Energy UK at 4.5, albeit from a smaller review pool, with excellent customer service and a smooth transition for those switching over.

They’ve been in business since 2001 and aspire “to be pioneering champions of green and sustainable energy in the UK and to delight our customers”.


Ecotricity, established back in 1996 is one of the longest standing renewable energy companies. Their mission is simple:

“To change the way electricity is made and used in Britain”.

They guarantee 100% green electricity and carbon neutral green gas. Their renewable sources are wind, solar and hydro. Their profits are invested into further renewable projects such as wind and solar farms and they own a grass-fed green gas mill though you won’t get 100% green gas from the company. Ecotricity is the only energy company to get a stamp of approval from the Vegan Society. If you are looking for an ethical option, this may be the energy company for you as they also fund and support anti fracking campaigners and have followed in the footsteps of Extinction Rebellion to declare a climate emergency.

In 2020 they were awarded the title as one of the greenest energy suppliers in the UK by ‘Which?’. They are also responsible for a number of electric vehicle points across the UK making electric car drives lives easier.

Their tariffs include one simple rate with no contract and no exit fee. There are however some negative reviews on Trust Pilot around closing accounts and switching away from Ecotricity to bear in mind.

Octopus Energy

Another big player in the renewable energy supply, Octopus has a strapline ‘doing energy better’ which rings true. They won 1st place in the 2019 Which? survey as a recommended supplier. As well as winning awards for customer satisfaction, 97% of the company's 22,000 reviews on Trustpilot are rated good or excellent. That's very rare for an energy company, and means Octopus has the maximum five-star rating on Trustpilot. Launched in 2016, they supply their customers, in the region of 1.4 million UK homes with 100% renewable energy only.

They offer a tariff with 100% renewable electricity and carbon offsetting for gas, a tariff that includes perks for electric vehicle drivers as well as a tariff that tracks wholesale energy prices with customers able to view daily costs. They promise to make sure that any carbon involved in the production of your gas will be offset and to do this they have partnered with Brighton-based charity Renewable World which specialises in carbon reduction projects.

Octopus has strong green credentials with a policy of investing into sustainability projects and research. They are well-respected for their company ethics and transparent green tariffs with no exit fees. Their tariffs are some of the cleanest and cheapest deals you can find in the UK.


Bulb is an excellent choice if you have renewable energy technology in your home because it allows you to sell your excess energy back to the grid.

They make things simple by offering one variable tariff with 100% renewable electricity and 10% green gas with the rest of the gas supply being offset by carbon reduction projects. A variable tariff means that you can benefit if the wholesale price of energy drops but you need to bear in mind that the extra cost is also passed on to you if the price goes up. The average customer can reduce their carbon footprint by 3.5 tonnes per year. Bulb also doesn’t charge an exit fee for switching to another energy supplier. Each time someone switches to them as their energy supplier they donate £1 to a children’s education charity about growing your own food. Plus, if you recommend a friend, you’ll both get £50. 

They have a good reputation for customer service with a score of 4.7 on trust pilot. They are known for an easy transition, fair prices, and transparency on bills. Launched in 2015, they have become increasingly popular supplying over 1.4 million homes, which is in no small part down to their affordability. 

Bulb buys its energy from independent generators, such as hydropower, solar and wind so it can guarantee its electricity is 100% green. The 10% green gas comes from renewable sources such as food and farm waste with the rest being offset by supporting carbon reduction projects around the world making its gas 100% carbon neutral.

Ovo Energy

Launched in 2009, Ovo Energy was one of the new kinds of digital challenger brand looking to take on the Big Six. In 2019, Ovo Energy acquired SSE and its 3.5 million customers, technically making it one of the Big Six. However, they are running the two brands separately for now.

Ovo Energy prides itself on excellent customer service which is backed up by 87% of reviews on Trust Pilot though not as highly rated as Octopus currently. Their renewable energy sources include Anaerobic digestion, solar, wind and hydro. One thing to bear in mind though is that Ovo Energy charge a £30 exit charge per fuel.

With 100% renewable electricity, Ovo also provides 100% carbon neutral gas for members of the Ovo Beyond scheme, which is made up of 15% green gas and 85% offset using carbon reduction projects like the Katingan project in Indonesia, which invests in peatland restoration and protection.

They pledge to plant a tree in your name every year, through a partnership with the Woodland Trust, when you switch to them and they also support charities through the Ovo Foundation.

The best way to find a cheap green energy tariff is to use a comparison website. Most will let you filter the results, so you just see renewable tariffs. There are many comparison websites to choose from. To find your cheapest deal, grab a recent bill from your current provider so you know how much gas and electricity you're using for an accurate comparison and go from there.

Author Image

Richard is a seasoned director and a respected authority in the field of renewable energy, leveraging his extensive experience working with and for large PLC's in the AEC (Architecture, Engineering & Construction) industry.

He has worked on hundreds of projects across the United Kingdom like HS2 and other major critical highways and infrastructure projects, both for the public and private sectors.

He is one of the chief driving forces behind the creation, development, and management of The Renewable Energy Hub, your premier online destination for sustainable energy knowledge and resources.


Find a local installer

Welcome to the biggest directory of UK renewable energy companies



Compare prices from local companies fast & free

Enter your postcode to compare quotes from leading professionals. We promise to keep your information Safe & Secure.

Privacy Policy

Contact Us

What technology are you looking to install?

What do you require?

Please enter your contact details