Shell Energy loses ground in UK clean power rankings as British Gas closes the gap
Shell Energy's whole-portfolio renewable share fell from 71% to 50% in the latest Clean Power Index after demand growth outpaced certificate procurement.
Shell Energy's share of renewable electricity in its total supply portfolio dropped from 71% to 50% in the latest annual Clean Power Index, published Wednesday (2026-09-02), as its electricity volumes expanded but its procurement of renewable certificates failed to keep pace.6
The finding lands at an awkward moment for the supplier and puts fresh pressure on Ofgem. Research firm Matched Energy, which produces the index, has called on the regulator to require suppliers to report renewable coverage by the hour rather than on an annual portfolio basis — a change that would expose the gap between a "100% renewable" marketing label and what physically flows to a customer during a winter evening peak.6
British Gas moved in the opposite direction, lifting its score from roughly one-third to 42%, according to the index. Good Energy led all household suppliers selling a renewable tariff at 87%, while Ovo sat at the bottom with a 2% whole-portfolio score.6
Shell Energy's decline is partly a volume problem. Its total electricity supply expanded from 3.6 TWh to 4.6 TWh, but "its certificates did not keep pace," Matched Energy said. Shell also announced Monday (2026-08-03) the sale of its European onshore renewables portfolio to TotalEnergies, a transaction post-dating the index measurement period but confirming a wider strategic retreat from European renewable assets.6,5
Matched Energy founder Joe Kwiatkowski was unsparing about what the "100% renewable" label delivers in practice. "If you turned the heating on at 6pm on a January weekday, most of your '100% renewable' supply was not matched by renewable generation at all," he said. Even Good Energy, the index's top scorer, leaves 13% of its customers' consumption uncovered by renewables, Matched Energy noted.6
If Ofgem adopts hourly matching as the regulatory standard, the implications for retail procurement are significant. Annual certificates would no longer suffice. Suppliers would need to match generation to consumption hour by hour, which would push both procurement complexity and certificate costs higher across the board.6
UK nuclear policy sits in the background of this debate. The government struck a deal with EDF on Wednesday (2026-07-08) to extend the 1.2 GW Sizewell B nuclear power station by 20 years to 2055, granting it a fixed-price contract for difference, the first such CfD awarded to a nuclear plant, Montel reported. Sizewell B currently supplies around 3% of Britain's electricity, enough to power approximately 2.5 million homes. Low-carbon baseload at that scale is relevant to any supplier trying to improve its portfolio score, but it does not resolve the hourly matching problem that underpins Matched Energy's complaint.4,3
The larger nuclear question is Sizewell C. EDF's proposed plant is expected to produce up to 3.2 GW once operational, and the government projects annual electricity system savings of around £2 billion compared with alternative low-carbon technologies. Costs have escalated sharply: the total price tag has roughly doubled since the 2016 estimate of £18 billion, reaching around £35 billion, after EDF added a projected £2.16 billion to the forecast in February (2026-02).1
Public accounts committee chair Sir Geoffrey Clifton-Brown has warned that the project carries "exceptional scale, complexity and significance for taxpayers," a characterisation that signals sustained parliamentary scrutiny of its funding structure. EDF's half-year report noted manufacturing progress on the Unit 1 reactor pressure vessel and £5 billion in export credit financing guaranteed, but civil works and engineering delivery remain ongoing.1,2
For retail suppliers, the index result is the more immediate problem. Shell Energy's whole-portfolio score of 50%, combined with its exit from European renewable assets, charts a company pulling back from clean energy commitments in its largest market. British Gas's improvement to 42% runs the other way. How Ofgem responds to Matched Energy's call for hourly matching — and whether it becomes a binding disclosure requirement — will shape retail procurement costs and the market value of UK renewable certificates for years ahead.6,5