100Green OVO Energy (August 2026)
Overview
100Green wins based on its cheaper fixed tariff and top-tier customer service scores, though OVO Energy is better for app quality.
100Green leads across the majority of metrics in this comparison, offering a lower-priced fixed tariff and ranking first for customer service with Citizens Advice. OVO Energy provides a cheaper standard variable tariff and holds higher app ratings, but 100Green's overall service scores give it the edge.
About 100Green and OVO Energy
Who is 100Green?
Set up in 2001 as Green Energy UK, 100Green is an independent, smaller supplier that focuses on environmentally friendly energy. It appeals to customers who want strict environmental standards rather than competing on size with the UK's largest suppliers.
Who are OVO Energy?
Set up in 2009, OVO Energy is one of the UK's largest domestic suppliers. It grew significantly in 2020 when it bought the household energy business of SSE, which increased its scale. Recently, an agreement was announced for OVO to become part of E.ON, a planned move that is subject to regulatory approvals.
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Tariffs and pricing
100Green offers the lowest-priced overall tariff in this comparison. Its cheapest deal is a 12-month fixed plan, Exclusive Spring 100% Green 12M August 27, which costs £1,749 a year and carries no exit fees. OVO Energy's cheapest overall option is its Simpler Energy standard variable tariff, which has no fixed term and costs £1,805 a year.
Looking specifically at fixed deals, 100Green is £175 a year cheaper. OVO Energy's lowest-priced 12-month fixed tariff costs £1,923 a year and includes a £100 total exit fee. Conversely, households seeking a variable plan will find OVO Energy's tariff is £171 a year cheaper than 100Green's Sparkling SVT variable option.
100Green and OVO Energy: Tariff Options
100Green tariffs
100Green offers standard variable and fixed-rate options for households. Its fixed plans lock in prices for 12 months.
OVO Energy tariffs
OVO Energy offers standard variable and fixed tariffs. Its fixed plans last for 12 months and include options to bundle extra services like boiler cover or green electricity. It also offers a specialist add-on for electric vehicle owners.
Customer reviews
Both suppliers hold high Trustpilot scores. OVO Energy maintains a 4.7 out of 5 rating from over 293,000 reviews, with 77% of these being five-star. 100Green has a 4.6 out of 5 rating from a smaller base of 1,539 reviews, where 74% are five-star ratings.
Reviewers frequently highlight 100Green for its helpful staff, noting quick response times and efficiency in resolving queries. OVO Energy customers also mention polite and efficient staff, though some report difficulties reaching customer service and long wait times.
In the Which? customer satisfaction survey, 100Green scores 72, compared to 61 for OVO Energy. 100Green performs better across most sub-scores, including a 4 out of 5 for overall customer service, whereas OVO Energy scores 2 out of 5. However, OVO Energy achieves 9 out of 10 for helping those who need it, compared to 100Green's 4.
Mobile apps
OVO Energy holds a clear advantage in app ratings. Its iOS app scores 4.6 out of 5 from 18,000 ratings, and its Android app scores 3.0 out of 5 from over 10,000 ratings. Both apps have been updated recently with performance improvements and new smart features.
100Green's apps have very small sample sizes. The iOS app scores 1.1 from just 21 ratings, and the Android app scores 1.2 from 30 ratings. While these samples are too small to compare directly against a supplier with tens of thousands of ratings, recent iOS reviews for 100Green frequently cite basic design and poor usability.
Service and support
100Green ranks 1st in the Citizens Advice table with an overall score of 4.33 out of 5, while OVO Energy ranks 8th with a score of 3.3 out of 5. Both suppliers have formal vulnerability commitments registered with Citizens Advice.
100Green records an average call centre wait time of just 7 seconds, which is notably faster than OVO Energy's average of 1 minute 33 seconds. For written communication, OVO Energy responds to 98.5% of emails within two days, slightly ahead of 100Green at 90.9%.
OVO Energy reports an average social media response time of 6 minutes 53 seconds. 100Green does not currently publish this metric.
Complaints and performance
In the first quarter of 2026, 100Green received 144 complaints for every 100,000 customers. During the same period, OVO Energy received 1,725 complaints per 100,000 customers. This means 100Green had far fewer complaints than OVO Energy.
Green Energy Comparison
100Green's green energy
100Green has a 100% renewable electricity mix. As well as this, it supplies 100% green gas to its customers, sourced from anaerobic digestion. It does not use carbon offsetting, choosing instead to buy renewable energy and green gas directly. You can find out more about its environmental work on its website.[1]
OVO Energy's green energy
OVO Energy's electricity mix is largely fossil fuels, with some renewable and nuclear energy. Despite this, the company has a "Plan Zero" mission to cut its carbon footprint. Customers can choose to add a greener electricity upgrade to their plan. To support the environment, OVO has planted 5 million trees in the UK to help absorb carbon.[2]
Our verdict
| If you care most about | Choose |
|---|---|
| The lowest annual cost on our assumptions | 100Green |
| Overall customer service | 100Green |
| A well-rated mobile app | OVO Energy |
| A greener fuel mix | 100Green |
100Green wins based on its cheaper fixed tariff and top-tier customer service scores, though OVO Energy is better for app quality.
100Green leads across most price and customer service metrics in this comparison. It offers a lower-priced fixed tariff, charges no exit fees on its plans, and ranks at the top of the Citizens Advice table, supported by fast call answering times.
OVO Energy may suit households who prioritise app management or want the cheapest standard variable tariff. However, based on its high customer service scores and lower fixed pricing, 100Green is likely the stronger choice for most households.
- Cheaper fixed tariff
- No exit fees
- Ranks 1st with Citizens Advice
- Fast call centre response times
- Higher standard variable tariff
- Very poorly rated apps
- Cheaper standard variable tariff
- Highly rated iOS app
- Large volume of positive Trustpilot reviews
- Higher fixed tariff costs
- £100 exit fee on its cheapest fixed deal
- Longer call wait times
Frequently asked questions
Which supplier is better overall?
100Green performs better across most of the data we compared. It offers a cheaper fixed tariff and ranks first for customer service with Citizens Advice. OVO Energy is better for app quality and has a cheaper standard variable tariff.
Does 100Green or OVO Energy have cheaper fixed deals?
100Green has the cheaper fixed deal. Its 12-month fixed tariff costs £1,749 a year, which is £175 cheaper than OVO Energy's cheapest fixed option.
How do Trustpilot reviews compare for 100Green and OVO Energy?
Both have strong ratings. OVO Energy scores 4.7 out of 5 from over 293,000 reviews, while 100Green scores 4.6 out of 5 from around 1,500 reviews.
Which supplier has the better mobile app?
OVO Energy has a much stronger app experience. Its iOS app scores 4.6 out of 5 from 18,000 ratings. 100Green's apps have very few ratings and score poorly in the small sample available.
Who answers the phone faster?
100Green has an average call centre wait time of just 7 seconds, making it much faster than OVO Energy, which averages 1 minute 33 seconds.
Should I choose 100Green or OVO Energy?
100Green is the stronger choice if you want a cheaper fixed tariff and excellent customer service. Choose OVO Energy if you prefer to manage your energy through a highly rated mobile app or want a cheaper standard variable tariff.
Do these suppliers charge exit fees?
100Green does not charge exit fees on its fixed tariffs. OVO Energy charges a £100 total exit fee on its cheapest fixed deal.
Which supplier ranks higher with Citizens Advice?
100Green ranks 1st in the Citizens Advice table with a score of 4.33 out of 5. OVO Energy ranks 8th with a score of 3.3 out of 5.
Which supplier scores higher with Which?
100Green scores 72 in the Which? customer satisfaction survey, compared to 61 for OVO Energy. 100Green performs better on overall customer service, though OVO Energy scores higher for helping those who need it.
Who has the cheaper standard variable tariff?
OVO Energy's standard variable tariff costs £1,805 a year, which is £171 cheaper than 100Green's variable option.
What changed this month
This month, OVO Energy's iOS app days since last update rose from 13 to 37, OVO Energy's play store days since last update rose from 14 to 37, and 100Green's play store days since last update rose from 15 to 38. There were 20 other data changes this month — see the full changelog below for details.
Data changes this month (30)
100Green
- Trustpilot reviews1,511 → 1,539
- iOS app ratingnow available (1.1)
- iOS app ratings countnow available (21)
- iOS app days since last updatenow available (38)
- iOS app updates in last 90 days0 → 3
- iOS sampled reviews avg starsnow available (1)
- iOS sampled negative reviews0 → 3
- Play Store days since last update15 → 38
- Avg social media response time55 → no longer available
- Cheapest fixed tariff£1,671.16 → £1,748.8
- Cheapest tariff£1,671.16 → £1,748.8
OVO Energy
- Trustpilot reviews287,327 → 293,863
- iOS app days since last update13 → 37
- iOS app updates in last 90 days3 → 2
- iOS sampled reviews avg stars4.2 → 3.67
- iOS sampled positive reviews4 → 2
- Play Store rating3.2850413 → 3.0206423
- Play Store ratings count10,351 → 10,621
- Play Store days since last update14 → 37
- Play Store positive ratings %55.4 → 48.2
- Play Store negative ratings %40.2 → 46.9
- Play Store neutral ratings %4.5 → 4.9
- Play Store net-positive %15.2 → 1.3
- Cheapest fixed tariff£1,797.13 → £1,923.42
- Cheapest tariff£1,797.13 → £1,804.82
- Cheapest tariff exit fee£100 → £0
- Cheapest tariff term12 months → 0 months
- Tariff count5 → 4
- Fixed tariffs available4 → 3
- Longest fixed term24 months → 12 months
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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.