From food to fuel: UK retailer to transform supermarket industry’s approach to waste disposal

Posted by Isobel Drake on 26th August 2008

Waitrose has become the first major UK retailer to embark on a wide scale trial of anaerobic digestion. The concept is to convert waste food into renewable energy in a pioneering trial which may transform the way that the supermarket industry disposes of its waste.

The retailer is using all of the food waste from five of its shops to generate renewable energy, which goes back into the national grid. If successful, the scheme could be rolled out to far more Waitrose shops and provide an environmentally friendly alternative to sending waste food to landfill.

Anaerobic digestion, the process in which microorganisms break down biodegradable material, is an eco-friendly waste management system which breaks down food waste. This process of heating the waste produces a methane rich bio-gas which is turned into heat and electricity as an efficient alternative to fossil fuels. The process effectively eliminates the need to send waste into landfill sites – a process which emits methane gas into the atmosphere and contributes towards global warming.

The anaerobic digestion process wastes nothing along the way, with the heat generated continually re-used during the anaerobic digestion process and leftover residue providing an odourless organic fertiliser for growing crops.

Recycling

The food waste at the five Waitrose stores is collected by recycling experts, Cawleys, who take it to an anaerobic digestion plant where it is converted into electricity.

The electricity generated at this plant goes into the national grid and currently has the capacity to provide the power requirements of over 500 homes.

Waitrose Recycling & Waste manager, Arthur Sayer, suggests that similar operations have been successful in other European countries and trial of the process appeared a suitable way to limit their impact on the environment. “Waitrose is continually looking at ways of reducing its impact on the environment. Anaerobic digestion has been operating in other European countries, such as Germany for decades, so we thought it was well worth trying out on a commercial scale for our supermarkets,” he said. “So far the signs are really positive – and this looks to be a sustainable way of eliminating the need to send waste food to landfill.”

Jon Cawley, Managing Director of Cawley’s, believes the Waitrose trial will be warmly received by consumers. “Consumers will be delighted that Waitrose is pioneering the use of anaerobic digestion in the retail market. It shows that retailers can make positive environmental changes at all stages in the food chain, treating food waste management as seriously as food sourcing and creating a positive circle whereby food waste can be recycled back to fertiliser for the land in a process which produces renewable energy, and avoids sending waste to landfill where it can produce greenhouse gases,” he advised.

“It’s not just food waste that goes into the anaerobic digestion process, other biodegradable products including paper plates and napkins and corn starch packaging can also be broken down to produce energy,” he added.