Londonist is a bit Christmas Tree obsessed this year. In the past few weeks we've had three tree posts. Only one of those was about the Trafalgar Square tree, but it seems we missed something: it runs on hydrogen.
According to the London Asembly site "For the first time ever the Trafalgar Square Christmas Tree lights are being powered by a hydrogen fuel cell, a clean form of energy."
The hydrogen fuelled tree is being sponsored by the London Hydrogen Partnership, a consortium of public, private and voluntary organisations "working to establish the widespread use of hydrogen as a clean fuel for buildings, transport and other applications," who probably look nothing like Bunsen and Beaker from the Muppets.
The LHP also had a hand in the fuel cell buses (or 'Bus of the Future' as Ken likes to call them) which are currently trundling around Route 25.
If you want to see a picture of the fuel cell there's one on the Assembly's site, or you can always go visit it 'in person' in Trafalgar Square.
You'll have to be quick though because it's due to go 'on tour' soon at "public events across London". Maybe next year the fuel cell could run for Mayor?