Best Green Energy Suppliers in the UK (September 2026)
100Green ranks first on the qualifying September evidence at 91/100.
Overview
Quick summary
7 suppliers had qualifying evidence for September 2026. Suppliers are ordered using green-tariff availability, Trustpilot rating and Citizens Advice score. 100Green ranked first at 91/100. Tariff prices are shown only as supporting context and do not affect this score.
Top suppliers this month
- ★ #1 TOP PICK100Green91score out of 100
- #2Octopus Energy88score out of 100
- #3Good Energy86score out of 100
#1 100Green: 91/100. Trustpilot 4.6/5; Citizens Advice 4.3/5; and at least one tariff marked green in the qualifying data. For price context, Exclusive Spring 100% Green 12M September 27 was £1,717 a year under the common usage, region and payment assumptions.
#2 Octopus Energy: 88/100. Trustpilot 4.8/5; Citizens Advice 3.7/5; and at least one tariff marked green in the qualifying data. For price context, Flexible Octopus was £1,598 a year under the common usage, region and payment assumptions.
#3 Good Energy: 86/100. Trustpilot 4.8/5; Citizens Advice 3.5/5; and at least one tariff marked green in the qualifying data. For price context, Good Energy Standard was £1,710 a year under the common usage, region and payment assumptions.
Supplier highlights
100Green
TOP PICKWho they are: 100Green had enough September evidence to be included in this ranking.
Why choose them: It ranked 1st with 91/100. Trustpilot 4.6/5; Citizens Advice 4.3/5; and at least one tariff marked green in the qualifying data. For price context, Exclusive Spring 100% Green 12M September 27 was £1,717 a year under the common usage, region and payment assumptions.
Octopus Energy
Who they are: Octopus Energy had enough September evidence to be included in this ranking.
Why choose them: It ranked 2nd with 88/100. Trustpilot 4.8/5; Citizens Advice 3.7/5; and at least one tariff marked green in the qualifying data. For price context, Flexible Octopus was £1,598 a year under the common usage, region and payment assumptions.
Good Energy
Who they are: Good Energy had enough September evidence to be included in this ranking.
Why choose them: It ranked 3rd with 86/100. Trustpilot 4.8/5; Citizens Advice 3.5/5; and at least one tariff marked green in the qualifying data. For price context, Good Energy Standard was £1,710 a year under the common usage, region and payment assumptions.
E.ON Next
Who they are: E.ON Next had enough September evidence to be included in this ranking.
Why choose them: It ranked 4th with 86/100. Trustpilot 4.5/5; Citizens Advice 3.7/5; and at least one tariff marked green in the qualifying data. For price context, Next Fixed 24m Exclusive v11 was £1,510 a year under the common usage, region and payment assumptions.
OVO Energy
Who they are: OVO Energy had enough September evidence to be included in this ranking.
Why choose them: It ranked 5th with 84/100. Trustpilot 4.7/5; Citizens Advice 3.3/5; and at least one tariff marked green in the qualifying data. For price context, Simpler Energy was £1,611 a year under the common usage, region and payment assumptions.
Ecotricity
Who they are: Ecotricity had enough September evidence to be included in this ranking.
Why choose them: It ranked 6th with 80/100. Trustpilot 4.2/5; Citizens Advice 3.4/5; and at least one tariff marked green in the qualifying data. For price context, EcoFixed - 2 Year August 26 v4 was £1,559 a year under the common usage, region and payment assumptions.
So Energy
Who they are: So Energy had enough September evidence to be included in this ranking.
Why choose them: It ranked 7th with 79/100. Trustpilot 4.5/5; Citizens Advice 2.9/5; and at least one tariff marked green in the qualifying data. For price context, So Green Tracker 24m was £1,508 a year under the common usage, region and payment assumptions.
Methodology
This page uses September 2026 evidence and orders suppliers by green-tariff availability, Trustpilot rating and Citizens Advice score. Missing criteria are not silently estimated. The annual tariff figure is supporting price context and is not part of the score. All price figures use a representative East Midlands postcode, Monthly Direct Debit and the stated Ofgem medium-use assumptions. Electricity-only, gas-only and dual-fuel rows may appear; readers should compare like with like and obtain a personalised quote before switching.
All ranked suppliers (7)
Suppliers ranked by the evidence criteria shown below.
| # | Supplier | Overall score | Ratings and green tariff | Estimated annual cost |
|---|---|---|---|---|
| 1 | 100Green | 91 | Trustpilot 4.6/5 · Citizens Advice 4.3/5 · Green tariff available | £1,717/yr |
| 2 | Octopus Energy | 88 | Trustpilot 4.8/5 · Citizens Advice 3.7/5 · Green tariff available | £1,598/yr |
| 3 | Good Energy | 86 | Trustpilot 4.8/5 · Citizens Advice 3.5/5 · Green tariff available | £1,710/yr |
| 4 | E.ON Next | 86 | Trustpilot 4.5/5 · Citizens Advice 3.7/5 · Green tariff available | £1,510/yr |
| 5 | OVO Energy | 84 | Trustpilot 4.7/5 · Citizens Advice 3.3/5 · Green tariff available | £1,611/yr |
| 6 | Ecotricity | 80 | Trustpilot 4.2/5 · Citizens Advice 3.4/5 · Green tariff available | £1,559/yr |
| 7 | So Energy | 79 | Trustpilot 4.5/5 · Citizens Advice 2.9/5 · Green tariff available | £1,508/yr |
Use our referral link, and we'll both get £50 credit once your switch is complete.
Existing customer? Find out how you can benefit too. T&Cs apply (only one switching offer per household)
Our verdict
100Green ranks first on this page’s September evidence.
100Green scores 91/100 using green-tariff availability, Trustpilot rating and Citizens Advice score.
Use the evidence rows alongside price and tariff terms; a higher score is not a guarantee that a supplier is the best fit for every household.
Frequently asked questions
How is this page ranked?
Suppliers are ranked using green-tariff availability, Trustpilot rating and Citizens Advice score. Missing evidence is shown or excluded according to the stated rule rather than being guessed.
Are these personalised prices?
No. Prices use an East Midlands representative postcode, Monthly Direct Debit and Ofgem medium-use assumptions. Your quote can differ with location, usage, meter and eligibility.
Does a variable or tracker tariff always have no exit fee?
No. Tariff type, contract term and exit fee are separate. Check the named tariff’s term and exit fee before switching.
Why can rankings move sharply between months?
The monthly table is rebuilt from the qualifying evidence available for that month. A tariff entering, leaving or changing price, or a rating or service measure changing, can move a supplier or tariff several places.
What does missing data mean?
It means the relevant comparable figure was not present under this page’s filters. Missing values are not estimated; check the supplier directly for current availability and a personalised quote.
Written by
Rob Gibbs
Hi, I'm Rob, and I run Energy-Review.co.uk. I initially started this project in 2018 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 have spent 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.
What changed this month
This month, cheapest annual cost fell from £1,561 to £1,508.
Data changes this month (1)
- Cheapest annual cost£1,561 → £1,508
Related articles
Best Energy Supplier Apps in the UK
14 suppliers had qualifying evidence for September 2026. Suppliers are ordered using the mean of qualifying iOS App Store and Google Play ratings; each store rating needs at least 50 ratings, and one qualifying store is enough. Scottish Power ranked first at 95.3/100. Tariff prices are shown only as
Read article →Best No-Exit-Fee Energy Suppliers in the UK
16 suppliers had qualifying evidence for September 2026. Suppliers are ordered using each supplier’s cheapest tariff with a £0 exit fee. The ranking is price-based: Home Energy had the lowest qualifying annual cost at £1,453.
Read article →
Cheapest Energy Suppliers in the UK
63 tariffs from 16 suppliers met the common September 2026 filters. Home Energy’s Fair Variable Dual ranked first at £1,453 a year (£121 a month). Prices are estimates for the stated usage, region and payment method, not personalised quotes.
Read article →Related guides
How to Choose a Green Energy Supplier in the UK
Before comparing suppliers, it helps to know how they back up their green claims. When you sign up for a green tariff, the electricity flowing into your home is exactly the same as your neighbour's. All power mixes together in the National Grid. A green tariff simply means your supplier promises to
Read guide →
Which energy suppliers are going bust?
The UK energy market has seen massive upheaval over the past few years. During the peak of the energy crisis in 2021 and 2022, wholesale costs soared and caused dozens of suppliers to collapse. By July 2026, the market has largely stabilised. However, smaller companies still occasionally fail, and t
Read guide →
Who is cheaper than British Gas? (2026)
British Gas is one of the UK's largest energy suppliers, but staying on its default standard variable tariff is currently one of the most expensive ways to pay for your gas and electricity. Following a 13% rise in the Ofgem price cap on 1 July 2026, household energy bills have jumped again, driven b
Read guide →