100Green OVO Energy (September 2026)
Overview
There is no single best choice: compare price, service, app and green-energy evidence separately.
About 100Green and OVO Energy
Who is 100Green?
100Green is an independent energy supplier based in Hertfordshire. Set up in 2001 as Green Energy UK, it is operated by Green Energy (UK) Ltd and is one of the UK's oldest suppliers outside the main group of large energy firms. It has a small market share but focuses on green energy and customer service.
Who are OVO Energy?
OVO Energy was set up in 2009 and is backed by the Ovo Group. It grew quickly and bought the household energy business of SSE in 2020, making it one of the UK's largest domestic energy suppliers. In May 2026, OVO announced a planned sale of its UK household energy business to E.ON, a deal that is waiting for approval from regulators.
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Tariffs and pricing
OVO Energy provides the cheaper overall deal in this comparison. Its Simpler Energy variable tariff costs £1,611 a year, while 100Green's lowest-priced option—the Exclusive Spring 100% Green 12M September 27 fixed tariff—is priced at £1,717 a year. This makes OVO Energy's cheapest option £106 cheaper annually, or roughly £9 a month.
Households seeking to lock in their rates will find 100Green cheaper for fixed deals at £1,717 a year, compared to OVO Energy's lowest fixed option at £1,742 a year. Both of these fixed tariffs last for a 12-month term. However, 100Green applies no exit fee, whereas OVO Energy charges £100 if you leave before the term ends.
Neither supplier charges exit fees on their absolute cheapest overall tariffs. It is worth noting the structural difference between the two: OVO Energy's lowest price is a variable rate, whereas 100Green's cheapest overall option is a 12-month fixed deal.
100Green and OVO Energy: Tariff Options
100Green
100Green offers standard variable and fixed tariffs for household customers, as well as smart and specialist options for homes with electric vehicles, batteries, or solar panels.
OVO Energy
OVO Energy gives customers a choice of standard variable and fixed tariffs, alongside specialist add-ons for electric vehicle owners.
Customer reviews
Both suppliers maintain strong Trustpilot profiles. OVO Energy achieves 4.7 out of 5, while 100Green scores 4.6 out of 5. OVO Energy holds a slightly higher five-star share at 78%, compared to 100Green's 74%, and its overall score is drawn from a significantly larger volume of nearly 300,000 ratings.
Reviewers for 100Green frequently highlight prompt phone answering and effective issue resolution. Customers often note the benefit of speaking directly with knowledgeable advisors. Conversely, a minority of users report occasional delays in service interactions and isolated billing discrepancies.
OVO Energy customers regularly commend staff for their patience when handling complex account problems, alongside positive feedback regarding prompt and efficient engineer visits. On the downside, some reviewers express frustration over long wait times and communication delays.
In the annual Which? survey, 100Green achieved an overall score of 72 out of 100, ahead of OVO Energy's 61. 100Green leads across several sub-categories, securing 4 out of 5 for customer service and 12 out of 15 for complaints handling. OVO Energy received 2 out of 5 and 6 out of 15 in those respective areas. However, OVO Energy performed better in the 'helping those who need it' category, scoring 9 out of 10 compared to 100Green's 4 out of 10.
App quality and ratings
OVO Energy demonstrates stronger app metrics, holding an App Store rating of 4.6 out of 5 across 18,000 reviews. 100Green records a much lower App Store rating of 1.1 out of 5, though this is based on a very small sample of just 21 ratings, limiting direct comparability with OVO Energy's larger user base.
On Google Play, OVO Energy scores 2.8 out of 5 from over 10,000 ratings, with more than a million installs. 100Green scores 1.2 out of 5 from 32 ratings. Both suppliers have updated their applications recently.
A recent sample of App Store feedback indicates that 100Green users often find the interface basic, difficult to read, and lacking functionality. In contrast, OVO Energy's reviewers generally describe its app as comprehensive and useful, although some users report loading issues on iPads and occasional website login difficulties.
Service and support
100Green performs strongly in Citizens Advice data, ranking 1st overall with a score of 4.33 out of 5. OVO Energy places 8th, achieving a score of 3.3 out of 5.
For phone support, 100Green records an average call centre wait time of just 7 seconds, compared to 1 minute 33 seconds for OVO Energy. 100Green also resolves social media inquiries more quickly, averaging 55 seconds against OVO Energy's 6 minutes 53 seconds.
OVO Energy is slightly faster at handling email correspondence, responding to 98.5% of emails within two days, compared to 90.9% for 100Green. Both suppliers maintain formal vulnerability commitments registered with Citizens Advice. For weekend support, 100Green operates its phone lines on Saturdays and Sundays, whereas OVO Energy remains closed.
Complaints and performance
Complaint figures are shown with each supplier’s reporting period. No winner is declared when periods differ or one figure is missing.
Green Energy Comparison
Published fuel-mix figures are shown only where both a source URL and reporting period are present in the stored data.
Our verdict
| If you care most about | Choose |
|---|---|
| The lowest annual cost on our assumptions | OVO Energy |
| Overall customer service | 100Green |
| A greener fuel mix | 100Green |
There is no single best choice: compare price, service, app and green-energy evidence separately.
Use the decision table to match the available evidence to the factors that matter most to your household.
- Cheapest variable tariff at £1,762 / year
- 4.6 Trustpilot from 1,559 reviews
- Top-1 Citizens Advice ranking
- 91% of emails answered within 2 days
- 94% of Google Play ratings are negative
- Cheapest variable tariff at £1,611 / year
- 4.7 Trustpilot from 299,269 reviews
- iOS app rated 4.6 out of 5
- 99% of emails answered within 2 days
- 52% of Google Play ratings are negative
Frequently asked questions
Which is cheaper, 100Green or OVO Energy?
On the stored annual-cost assumptions, 100Green is £1,717 and OVO Energy is £1,611. OVO Energy is lower by about £106 a year.
Can 100Green and OVO Energy complaint rates be compared directly?
No direct complaint-rate winner is declared because 100Green and OVO Energy do not both have figures for the same stated reporting period.
Which supplier leads on customer service?
On the comparable customer-service measure used in the decision table, 100Green leads.
Which supplier has the better app evidence?
The supplied data does not support a like-for-like app winner.
Do tariff eligibility rules matter?
Yes. Specialist, time-of-use, EV, heat-pump and export tariffs can have equipment, meter or account requirements. Check the current supplier terms before applying.
Which supplier has the greener evidence?
On the comparable green-energy measure used in the decision table, 100Green leads. This row is based on published fuel-mix percentages.
Which is better overall, 100Green or OVO Energy?
There is no single overall winner in this repaired draft. Price, service, app and green-energy evidence are kept as separate choices in the decision table.
When was this comparison updated?
The structured source payload is for September 2026.
What changed this month
This month, OVO Energy's play store net-positive % fell from 1.3 to -9.2, 100Green's iOS app days since last update fell from 38 to 25, and OVO Energy's iOS app days since last update fell from 37 to 25. There were 26 other data changes this month — see the full changelog below for details.
Data changes this month (32)
100Green
- Trustpilot reviews1,539 → 1,559
- Trustpilot 4-star %12 → 11
- Trustpilot 1-star %7 → 8
- Trustpilot positive reviews %86 → 85
- Trustpilot negative reviews %10 → 11
- Trustpilot net-positive %76 → 74
- iOS app days since last update38 → 25
- Play Store rating1.2413793 → 1.2258065
- Play Store ratings count30 → 32
- Play Store days since last update38 → 26
- Play Store positive ratings %3.4 → 3.2
- Play Store negative ratings %93.1 → 93.5
- Play Store neutral ratings %3.4 → 3.2
- Play Store net-positive %-89.7 → -90.3
- Avg social media response timenow available (55)
- Cheapest variable tariff£1,975.79 → £1,761.9
- Cheapest fixed tariff£1,748.8 → £1,717.28
- Cheapest tariff£1,748.8 → £1,717.28
OVO Energy
- Trustpilot reviews293,863 → 299,269
- Trustpilot 5-star %77 → 78
- Trustpilot 4-star %10 → 9
- iOS app days since last update37 → 25
- Play Store rating3.0206423 → 2.8167422
- Play Store ratings count10,621 → 10,825
- Play Store days since last update37 → 26
- Play Store positive ratings %48.2 → 43.2
- Play Store negative ratings %46.9 → 52.4
- Play Store neutral ratings %4.9 → 4.4
- Play Store net-positive %1.3 → -9.2
- Cheapest variable tariff£1,804.82 → £1,610.88
- Cheapest fixed tariff£1,923.42 → £1,742.03
- Cheapest tariff£1,804.82 → £1,610.88
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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.