Who are the best green energy suppliers in the UK? (2024)

Last updated: 2nd January 2024

Most energy suppliers in the UK now offer some options for green energy, but not all suppliers are equal. Some will charge you more, some don’t offer energy directly from a renewable source whilst others offer other ‘green’ perks alongside green energy.

In this post, we have highlighted who we think are the best green energy suppliers in the UK, focussing on green gas and green electricity tariffs, what they do in terms of renewable energy generation and we also look at price to see who is the cheapest green energy supplier.

The energy suppliers we have looked at who we consider to be the best are Octopus Energy, Ecotricity, 100Green, Good Energy and OVO Energy.

For our price comparisons, we will be using the following details across all suppliers:

  • East Midlands postcode
  • Direct Debit payment
  • Electricity usage: 2,500 kWh
  • Gas usage: 11,500 kWh
  • Dual Fuel tariff
  • Standard meter
Octopus energy review logo

Octopus Energy are the biggest supplier on this list. They started in 2015 and currently have over 6 million customers in the UK.


When it comes to electricity, all of the electricity supplied by Octopus is from renewable sources. For every amount of electricity you use on any of their tariffs, Octopus will make sure the same amount is added to the National Grid from renewable sources.


Octopus does not offer a green gas tariff, it used to offer a tariff called the “Octopus Supergreen tariff” that offset your gas usage but this is no longer available as of 2023.

Energy Generation

Octopus operates enough renewable generation to power 4 million homes making them one of the biggest investors in green energy in Europe. They also buy from over 700 green energy producers across the country. You can find out more here.

How cheap are Octopus for green energy?

Using our test criteria mentioned above, we got the following price for gas and electricity from Octopus for their cheapest renewable tariff:


Why choose Octopus?

If you are looking for renewable electricity as standard at the lowest price, then Octopus are likely to be a very good option. You will also be supporting an energy supplier that is very focused on adding as much green energy as possible back into the grid.

However, if you are looking for green or greener gas then Octopus may not be the right supplier for you. You can find out more about Octopus in our Octopus Energy review.

Ecotricity energy review logo

Ecotricity started in 1995 and has been focused on green energy since the beginning. They currently have around 200,000 customers.


They provide 100% renewable electricity as standard. About 12% of this is generated by themselves, whereas the rest is certified green energy from REGO certificates.


Ecotricity do not provide green gas, but they do offer carbon-neutralised gas as standard. About 1% of the gas they supply comes from green gas mills with the rest being standard natural gas. They do however offset the emissions produced by natural gas by investing in carbon reduction schemes worldwide.

Energy Generation

They have built 24 wind parks across the UK and 3 solar farms. In total, these provide electricity to supply over 60,000 homes across the UK. Find out more here.

How cheap are Ecotricity?

Using our test criteria mentioned above, we got the following price for gas and electricity from Ecotricity for their cheapest renewable tariff:


Why choose Ecotricity?

If you would like to support a smaller, green supplier but are conscious of costs, then Ecotricity might be the right supplier for you. You can support new renewable projects being built in the UK by being a customer whilst receiving renewable electricity and carbon natural gas.

If you are looking for the cheapest option or 100% renewable gas, however, then Ecotiricty might not be the right option. You can find out more about Ecotricity in our Ecotricity review.

100green logo

100Green have been around since 2001. They are another of the UK’s smaller suppliers although it is not known how many customers they currently have.


100% of 100Green’s electricity comes from renewable sources. They do not generate any of this themselves, but they match energy electricity customers use with REGO certificates.


100Green are the only supplier in the UK to offer 100% green gas. This comes from a mix of natural waste and organic material in a process called anaerobic digestion. They do not supply this themselves but instead work with independent generators across the UK. In a similar way to electricity, this gas usage is backed by Renewable Gas Guarantees of Origin (RGGOs). They have more information here.

Energy Generation

100Green do not generate any of their own energy, instead opting to work with independent generators. They do not appear to have plans to build any of their own renewable electricity or gas generators either.

How cheap are 100Green?

Using our test criteria mentioned above, we got the following price for gas and electricity from 100Green for their cheapest renewable tariff:


Why choose 100Green?

If you are looking for 100% green gas, then 100Green are the option for you. They are the only supplier on this list, and in the UK, to offer this. If you would like their green gas, this is not available on its own and so you would need a dual fuel tariff with electricity. This is also from 100% renewable sources, however.

If you are price-conscious, then 100Green may not be the best green energy provider as they are one of the more expensive suppliers. They also do not focus on building their own renewable generation which may be an issue for some, although they are instead working with independent generators.

You can find out more about 100Green in our 100Green review.

Good energy review logo

Good Energy have been around since 1999. They started as one of the first 100% renewable electricity suppliers and currently have about 200,000 customers.


Good Energy offer only 100% renewable electricity on all their tariffs, again this is through REGO certificates but 100% of the electricity used by customers is matched by the power they buy from their renewable generation partners.


10% of the gas from Good Energy comes from renewable sources. The other 90% is offset by investing in renewable projects across the world (in a similar way to Ecotricity). They work with an organisation called ClimateCare who focus on biogas generation.

Energy Generation

Good Energy do not own or operate any renewable generation themselves. In a similar way to 100Green, they choose to work with independent generators across the UK, they currently work with over 2,000 of these.

How cheap are Good Energy?

It is currently not possible to get a quote online for Good Energy. Once this becomes possible again, we will update this section.

Why choose Good Energy?

If you are looking for a smaller supplier with good green credentials, than Good Energy could be a good option for you. They offer renewable electricity tariffs and probably the second greenest gas tariff, with 10% green gas and the rest carbon offset.

If you would prefer 100% renewable gas, a provider that owns their own renewable generators or a larger supplier, then Good Energy may not be the right green supplier for you. You can find out more about Good Energy in our Good Energy review.

Ovo energy review logo

OVO was founded in 2009 and currently have around 5 million customers. They are the second biggest supplier in our list.


OVO do not offer renewable electricity across all their tariffs, something which differentiates them from every other supplier on our list. They do however offer a ‘green’ upgrade to their 1 year fixed tariff. This does get you 100% renewable electricity from UK generators. You also make a £20 contribution each year of having the tariff that goes to new renewable generators.


If you opt for the ‘Greener Energy’ upgrade, you also get greener gas. 10% of this gas comes from green gas generators throughout the UK, the other 90% is carbon offset. This appears to be exactly the same as what is offered by Good Energy mentioned above.

Energy Generation

OVO do not own any renewable generators like wind or solar farms. In a similar way to Good Energy and 100Green, they instead work with renewable generators across the UK.

How cheap are OVO Energy?

Using our test criteria mentioned above, we got the following price for gas and electricity from 100Green for their cheapest renewable tariff:


Why choose OVO Energy?

OVO are one of two big energy suppliers on our list (the other being Octopus Energy), so if you would like green energy from a big supplier they may be the right supplier for you. If you would greener gas from a big supplier, then they are currently your only option. You can also make a £20 contribution each year that you know is going towards helping renewable generators.

OVO however offers non-renewable electricity on most of their other tariffs and you may not want to support a supplier that does this. No other energy providers on our list do this. You can find out more about OVO in our OVO Energy review

The best green energy supplier is not always the cheapest but the price of energy is likely to be a big consideration for who you choose. The cheapest green supplier for electricity at the moment is Octopus Energy. For a property in the East Midlands, as an example, they currently charge a unit rate of 28.02p and a standing charge of 48.66p.

If you would like green gas, there is currently only one option available which is 100Green. This is not cheap at a unit rate of 9.99p and a standing charge of 32.66p, but as they are the only option they are the cheapest!

For comparison, the cheapest green alternative for gas (10% green, 90% carbon offset) comes from OVO at a cost of 6.74p per unit with a standing charge of 29.25p per day.

As we have seen above, when it comes to green energy there isn’t a supplier that fits everyone’s needs and there is no single best green energy supplier.

It comes down to where your priorities lie: are you looking for the cheapest green energy? Are you looking for 100% green gas and electricity? Are you more interested in supporting a supplier that works directly with local renewable energy sources? Would you prefer to be with a smaller or bigger supplier?

Here are our picks for a few different scenarios:

Cheapest supplierOctopus
100% green gas supplier100Green
Cheapest supplier of carbon offset gasOVO
Small supplier building their own renewable generatorsEcotricity

An image illustrating solar panels that may be used by the best green energy suppliers.

Green energy includes both electricity and gas sourced from renewable, environmentally sustainable methods.

For electricity, the focus lies on wind, solar, hydro, and biomass generation. Rather than directly supplying renewable electricity to customers, energy is instead purchased by suppliers and transported through the National Grid. Suppliers often use Renewable Energy Guarantees of Origin (REGO) certificates to assure consumers of the renewable origin. This means that although the energy you are using may not be from a renewable source, the energy purchased by your supplier to replace it on the National Grid will be.

Our article on REGOs goes into more detail, but these certificates can be traded and are not as eco-friendly as they seem. Some energy suppliers work directly with renewable energy providers (or even run their own) which is a more reliable way of knowing the energy you are receiving is actually from renewable sources.

For gas, green energy involves the utilisation of biomethane, produced through processes like anaerobic digestion or capturing methane emissions from organic waste. This biomethane serves as a sustainable substitute for conventional natural gas.


Hi, I'm Rob and I run I initially started this project 5 years ago when I was looking to switch energy suppliers and found there wasn't a website that provided simple, data backed reviews on all the suppliers available. Since then, I spent have a lot of time (too much some may say!) looking at all publicly available data about each supplier and writing reviews using this information. These reviews are updated as regularly as possible and any data is backed up by a source where necessary. I have also started writing guides on various energy related topics which hopefully you will find useful. If you find any issues, please use our contact form to let us know.

1 Comment
  1. Hi Rob. I have been with UW since 2009. I had solar panels fitted about 3 years ago and an air source heat pump about 6 months later. I am unable to have a smart meter on medical grounds but UW refuse to fit a bi-directional meter and insist I am to have a smart meter or nothing. OFGEM tell me I cannot be forced into having a SM or any Wi-Fi that makes me ill. How do I go about finding a supplier who will install the meter I require please? I have even offered to have an appropriate meter fitted and pay for this myself, OFGEM tell me that the supplier has to do this and explained why. Hope you can help regards Len

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