Food in a British supermarket too rotten to be sold is still being digested—by a plant that turns it into electricity to power the store. The Sainsbury's store says it's the first retail outlet in the country to remove itself from the national power grid, receiving electricity directly from a nearby anaerobic digestion plant that turns food waste from Sainsbury's outlets into bio-gas, the BBC reports. "Sainsbury's sends absolutely no waste to landfill and we're always looking for new ways to re-use and recycle," a company spokesman says.
At the digestion plant, expired food is placed in tanks and digested by bacteria that thrive without oxygen, breaking the food down into methane gas which is used to generate power, explains Popular Science, which notes that anaerobic digestion plants are planned for numerous US cities and the Kroger grocery chain has a distribution plant partly powered by old food. And there is plenty of room for expansion of the effort: More than a billion tons of food are wasted every year, with people in North America and Europe wasting around 220 pounds each, the Smithsonian finds. (A restaurant in Chicago, however, has managed to limit its waste to just 8 gallons in two years.)