Every day, the average supermarket throws out around $2,300 of food that sat on shelves a little too long. Some chains still send that food to landfills. But the U.K. supermarket chain Sainsbury’s is trying something different: Everything that can’t be donated to a food bank or otherwise used is turned into energy. Now, one of their local stores will be hooked up to that power so it can run entirely on food waste.
The company stopped sending food waste to landfills several years ago. “It was the right thing to do, but also it was the right commercial thing to do,” says Paul Crewe, head of sustainability at Sainsbury’s. “Putting food waste into landfill costs £150 per ton, and the alternative of [turning it into energy] is significantly cheaper. It’s putting that waste to true, positive use.”
The same trucks that deliver new food to each of Sainsbury’s 1,200 stores pick up waste on their way out, taking only what can’t be salvaged for charities or animal feed. The waste is delivered to biogas plants at a few locations around the country, where it’s turned into electricity.
Since one of the power plants happened to be only about a mile away from a supermarket, the company decided to build a direct power line to the store. “It made sense to ask, why couldn’t I put a cable directly from that facility directly to the store a mile away, and genuinely have the food waste from Sainsbury’s produce the electricity to run the whole store?” says Crewe. “That’s what we’ve achieved.”
Previously, the power went directly into the grid. All of the chain’s stores, across England, Wales, and Scotland, produce enough food waste to power about 3,000 homes a year, or three major superstores.
The project is as much about finding an alternative source for power as finding a use for the garbage. “It’s not just about the food waste, it’s about lots of combined technologies we’re looking at to help us become less reliant on the national grid,” explains Crewe.
Sainsbury’s already has two carbon neutral stores that run on gas from local farms and will be adding 165,000 solar panels to store roofs later this year.
The company is considering using biogas to power other retail locations, though the power may not come from food waste. “My food waste doesn’t necessarily have to go into them,” Crewe says. “I know it’s low carbon energy, and that’s what I’m desperately looking for.”