Building work is to begin on a new hydrogen refuelling station for buses in Hornchurch.
The plan was approved by a government planning inspector, after Havering Council, Essex, rejected the proposal.
The BP plant will provide green energy for buses which will operate between Ilford and London.
The council's decision to refuse permission for the plant was due to fears that storing hydrogen might be dangerous.
Part of an EU initiative
The plant was also opposed by local environmentalists who said it would damage the surroundings.
But a government planning inspector overruled the decision to oppose the plan, saying that in the long term the plant would be of benefit for the countryside as it would reduce dependence on CO2 emissions
The application was submitted by BP as part of a European initiative called 'Clean Urban Transport for Europe' (CUTE).
CUTE is a two-year pilot scheme involving nine European cities to demonstrate hydrogen cell technology for single-deck public buses as an efficient and environmental fuel of the future.
Three buses operating routes in central London would re-fuel in Hornchurch at the end of the day.
BP say they hope that the facility will be up and running in February next year.