Last October we launched the Clean Power Index: the UK's first accurate measure of the clean power energy suppliers actually deliver, hour by hour, across the whole year, built entirely from public data published by Elexon, NESO and Ofgem. Now the 2025-26 edition is taking shape. We have processed the settlement and certificate data for the compliance year that ended in March, and every supplier from last year's index is back — joined by three new business suppliers.
The chart below shows how every supplier's position changed between the two years.
View as table
| Supplier | 2024–25 rank | 2025–26 rank | Change |
|---|---|---|---|
| Good Energy | 1 | 1 | · |
| Bryt Energy | 2 | 2 | · |
| Pozitive Energy | — | 3 | NEW |
| Drax Energy Solutions | 3 | 4 | ▼1 |
| Eneco | — | 5 | NEW |
| Octopus | 5 | 6 | ▼1 |
| Ecotricity | 4 | 7 | ▼3 |
| 100 Green | 9 | 8 | ▲1 |
| So Energy | 11 | 9 | ▲2 |
| SSE | 8 | 10 | ▼2 |
| ENGIE Power | 13 | 11 | ▲2 |
| Brook Green Supply | 12 | 12 | · |
| SmartestEnergy | 10 | 13 | ▼3 |
| Shell Energy UK | 6 | 14 | ▼8 |
| Crown Gas & Power | — | 15 | NEW |
| British Gas Trading | 16 | 16 | · |
| TotalEnergies | 14 | 17 | ▼3 |
| SQE | 7 | 18 | ▼11 |
| Corona Energy | — | 19 | NEW |
| npower | 15 | 20 | ▼5 |
| EDF Energy | 18 | 21 | ▼3 |
| E.ON Next Energy | 17 | 22 | ▼5 |
| Scottish Power | 20 | 23 | ▼3 |
| Yu Energy | 19 | 24 | ▼5 |
| OVO Electricity | 21 | 25 | ▼4 |
| Fuse Energy | 22 | 26 | ▼4 |
| Utility Warehouse | 23 | 27 | ▼4 |
| Utilita | 24 | 28 | ▼4 |
| Outfox The Market | 25 | 29 | ▼4 |
What stands out
Three business suppliers join the index. Pozitive Energy, Crown Gas & Power and Corona Energy appear for the first time. Pozitive debuts at #3: 76% of the demand on its supply licence was matched, hour by hour, with renewable generation. That is a striking entrance — only Good Energy and Bryt Energy score higher. Hourly delivery is reaching the business market.
Good Energy holds the top spot. Its hourly score is 87%, a touch below last year's 88% — on a portfolio that grew 17%, from 0.41 TWh to 0.47 TWh. Its renewable purchases again covered 100% of its customers' demand across the year; the hourly score reflects how much of that demand was matched in the same half-hour.
Four suppliers fell a long way. Shell Energy UK dropped from #6 to #13: its customer demand grew from 3.6 TWh to 4.6 TWh, but its renewable certificate holdings did not keep pace, and its yearly renewable share fell from 71% to 50%. SQE dropped from #7 to #17: it redeemed certificates covering 40% of its demand this year, down from 93% last year. npower (#15 to #19) and E.ON Next Energy (#17 to #21) fell further back from positions that were already low.
The chasing pack tightened. So Energy (+3) and ENGIE Power (+3) both climbed on improved hourly scores, and British Gas improved its hourly score from 33% to 42% — enough to gain a place in a more crowded field.
Zeros are still zeros. Four suppliers — Fuse Energy, Utility Warehouse, Utilita and Outfox The Market — again redeemed no renewable certificates at all.
A note on how we ranked this
New entrants push everyone below them down the list, so a slip in position does not necessarily mean a supplier did worse. The chart only highlights suppliers that moved three or more places on a score change of three or more percentage points.
Both years are ranked on the same basis: the share of customer demand matched hour-by-hour with renewable generation, including biomass and excluding nuclear. Nuclear scores for 2025-26 cannot be calculated until suppliers publish their fuel-mix disclosures in autumn 2026, so we exclude nuclear from both years here to keep the comparison fair. This means 2024-25 positions in this chart differ slightly from last year's headline index, which included nuclear by default.
As always, the full methodology is published here, and you can explore both years supplier-by-supplier in the Clean Power Index. As before, we welcome engagement from any supplier that wants to understand its score. If that's you, get in touch.