Its new store in Diss incorporated redesigned fridges to keep the cold air in, the latest lighting technology in the freezers to keep energy down and more sky-lights to let in the sun's rays.

And in a first for a UK store, its roof was dominated by five large wind turbines which generate enough electricity to power the equivalent of 65 homes a year.

The aim was for the store to use 20pc less energy than other same-size stores - and Tesco chairman Sir Terry Leahy recently announced during a major speech on climate change that his Diss store had actually cut CO2 emissions by 29pc in its first year.

But last week it emerged that the five turbines, used to great effect during recent power cuts in Diss when the rest of the town lost electricity, had been removed.

Shoppers told the Mercury the turbines had gone missing from the roof tops months ago, with no explanation in store as to what had happened to them.

A spokesman for Tesco said: "The turbines have been removed from the Diss store. Another customer with the same model of turbine, not Tesco, has reported a problem with one of the turbines.

"I don't know what the problem was, but as a precaution we've removed all the turbines for health and safety reasons. We'll keep them down until they've found out the cause of the fault."

She could not say when the turbines were removed, or when they are expected to be returned.

But a customer services assistant in the store said that the turbines were removed before Christmas - and since then staff have had to deal with a stream of customers asking when they will be back.

Signs in the Tesco store still state "Our wind turbines generate enough electricity to power our checkouts." Others describe how cold air from the freezer section is pumped to the bakery area to keep customers cool there and how more sky-lights have led to a reduced lighting level in store.