The Waitrose store in Rickmansworth in Hertfordshire has linked up with electricity supplier green energy UK to receive its power from two tomato farms in Chichester and Stansted.
The combined heat and power units at the farms produce carbon dioxide to feed the tomatoes and generate heat as a by-product.
This warms the greenhouses and drives a turbine, creating electricity which is fully sustainable and meets all Waitrose Rickmansworth's electricity needs.
The Waitrose chain is owned by the John Lewis Partnership. Bill Wright, the partnership's Energy and Environment Manager, said: “All our branches source their electricity entirely from renewable sources, but we felt that so-called 'tomato power' was an idea worth exploring.”
“In addition to being environmentally sound, this surplus energy helps the farms generate additional income, so everyone benefits.”
Philippe Baradeau, Rickmansworth's Branch Manager, said: “This is helping us to promote our 'green' credentials.”
Doug Stewart, green energy's chief executive, said: “It's great to work with Waitrose on a project like this. It is an excellent piece of joined-up thinking.”