London restaurants are being asked to donate their waste grease, oil and fat, to help run a special power station.
Thames Water is one of the architects of the plan.
As Martin Stew reports, it hopes it could also lead to restaurants pouring less fat away, which clogs up the capital's sewers:
More top news
Prince Harry's Invictus Games is hailed a success as it closes with star performances from the Kaiser Chiefs, Ellie Goulding and Diversity.
Levi Roots from Brixton is the UK's richest reality star and Leone Lewis also makes the Top 10, but how did other Londoners fare?
The mayor is expected to be joined by his wife when he asks local Conservatives to choose him as their candidate in the general election.