The Irish Guards' regimental mascot, Conmeal the Irish wolfhound, was given his own sprig of shamrock by the Duchess of Cambridge.
The St Patrick's Day tradition dates back to 1901.
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Mayor of London Sadiq Khan is backing the scheme.
A spokesperson said the lightning strikes had left the "aircraft fuelling system unavailable."
Nearly 1,000 properties have been left without power, and road users have been warned of potentially hazardous conditions.