Sainsbury’s is accelerating its carbon-dioxide refrigeration programme thanks to early success.

Last week, the retailer opened its 100th carbon-dioxide store in Ely, Cambs and in doing so has cut its carbon footprint by 250,000 tonnes since the store-conversion programme began two years ago

Sainsbury’s announced the programme in 2009 when it said it planned to switch to carbon-dioxide for refrigeration and reduce its carbon footprint by a third.

It also committed to converting the first 135 stores to carbon-dioxide by 2014.

However, due to the success of the installation programme, the target for 2014 has been increased to 250.

The gases most commonly used in supermarket refrigeration are HFCs and HCFCs. These have a global-warming potential rating of 2,000-3,000, whereas that of carbon-dioxide is just one.

David Sheehan, Sainsbury’s director of store development, said: “When we began converting to carbon-dioxide, there was a severe shortage of expertise in the engineering community. However, the work we have carried out with our refrigeration suppliers to re-train engineers and grow the market for carbon-dioxide refrigeration has been so successful that we are now able to convert our estate much more quickly.

"As we continue to invest, we make the market for this technology more accessible to others. In this way, we hope that other companies will follow our lead.”