Big businesses are wasting £1.6bn a year on energy they could easily save through basic measures, according to the Carbon Trust Advisory.

The organisation says retailers stand to gain most from embarking on energy efficiency projects, but that not enough of them are doing so. It reports that the rate of return on these projects in the retail sector is 82%, compared to an average of 48% in other sectors, because the behavioural measures required need lower up-front investment.

Managing Director of the Carbon Trust Advisory Hugh Jones said: “The business case for energy efficiency is clear and compelling. Few other investments get anywhere near that rate of return.”

Some retailers have already taken the necessary steps. B&Q has saved 12% of its electricity emissions and 7% of its gas emissions, and is aiming to reduce its footprint by 90% by 2023.

The company has introduced an ‘eco champion’ in every store, who educates staff on energy efficiency.

Group CEO of Kingfisher plc and chairman of B&Q Ian Cheshire said, “Greening our business has made good economic sense. We are transforming ourselves into a low carbon business, which has not only enabled us to improve efficiencies but also create clear opportunities in growing sales of energy saving products.”

The Carbon Trust Advisory analysed 1,000 energy efficiency investments between 2006 and 2009, and interviewed finance directors at 100 UK companies.