Uswitch updated its green energy guide on 4 September 2026, setting out how it accredits renewable tariffs and publishing fuel mix figures for the largest suppliers1. The guide states that tariffs marked "Uswitch Green Tariff" must meet three standards: 100% of electricity bought directly from renewable generators, 70% of electricity sourced from renewable generation as it is used, and 10% of gas certified as renewable1.
Uswitch ranks tariffs into Gold, Silver and Bronze categories according to how much renewably sourced energy they include1. Its supplier table gives renewables in green electricity tariffs, renewables in the overall fuel mix, and zero-carbon fuels in the overall fuel mix, for the period 1 April 2024 to 31 March 20251.
| Provider | Renewables in green electricity tariffs | Renewables in overall fuel mix | Zero-carbon fuels in overall fuel mix |
|---|---|---|---|
| British Gas | 100% | 35% | 90% (55% nuclear) |
| EDF Energy | 100% | 18.2% | 73% (54.8%) |
| E.ON Next | 100% (Next Gust tariff only) | 31.3% | 34% (2.7%) |
| Octopus | Up to 100% | 86.4% | 100% (13.6%) |
| OVO Energy | 100% (Greener Electricity bolt-on) | 2% | 6% (4%) |
| ScottishPower | 100% | 7% | 11% (4%) |
The guide also lists smaller suppliers offering green tariffs. It states that 100Green is the only UK supplier offering 100% renewable energy across the board, including gas from anaerobic waste, and adds that "You will have to pay more though, as its tariffs aren't bound by Ofgem's price cap"1. Co-op Energy's tariffs are administered by Octopus and come with 100% renewable electricity, according to the guide1. Ecotricity supplies 100% renewable electricity, 10% of it generated by the company itself, and produces a small amount, 1%, of green gas for dual-fuel tariffs1. Good Energy's electricity tariffs are powered by 100% renewable energy generated in the UK by independent producers, with 10% of its gas from biogas1. All but one of So Energy's plans promise 100% renewable electricity, the exception being its So Flex standard variable tariff1.
"We rank each tariff into Gold, Silver, and Bronze categories based on the amount of renewably-sourced energy they include"
Why it matters for households
A supplier's fuel mix describes the fuels used to generate electricity for all of its customers, not just those on a green tariff, so the two columns in the table can differ sharply. OVO Energy's green electricity tariff is listed at 100% renewables through its Greener Electricity bolt-on, while renewables make up 2% of its overall fuel mix1. British Gas shows 100% for its green tariffs against 35% across its whole supply1.
For a household, the distinction determines what a green tariff actually changes. The guide notes that getting renewable energy is the same as getting energy generated from fossil fuels, that the supply itself is not different and is not affected during times of lower generation, and that green tariffs can sometimes cost more than other tariffs, though it says price differences are getting smaller1. It also notes that it can be difficult to know how green a tariff is, which is the gap the accreditation scheme is intended to address1.
Households generating their own power are covered separately: the guide describes solar panels, air source heat pumps and ground source heat pumps, and notes that excess electricity can be sold back to the grid1. It reports that two-thirds of people surveyed in 2026 said they were willing to pay more for a house with renewable or low-carbon energy sources such as solar panels, heat pumps or EV chargers if it guaranteed lower energy bills in the longer term1. It also states that in 2025 renewables made up just over half of the UK's electricity generation1.
What happens next
The guide carries no dated next steps. The fuel mix figures cover 1 April 2024 to 31 March 2025, and no date has been reported for their next update1.
Sources1 cited
- Green energy: stats, guides and deals - Uswitch, uswitch.com