This Grocery Store Will Be Powered By Its Own Waste
Microbes digest tossed food, belch up electricity-generating methane
Globally, more than a billion tons of food are wasted every year, with people in North America and Europe wasting about 220 pounds each. A grocery store chain in England is hoping to cut their contribution to this food waste dilemma by generating electricity from food no longer fit for sale.
Food waste comes from many places: crops are damaged in transit; restaurant goers have more on their plates that they can chew; grocery stores can't sell everything they put on the shelves. At the end of the day, food past its sell-by date is sometimes donated to charities, or given to animals. Sainsbury's, a grocery chain in the UK, is adding one more step to step to that food use ladder: they're feeding what's not fit for animal consumption to microbes.
When some microbes digest food, they belch up methane. Instead of letting that happen slowly in a dumpster and landfill, Sainsbury's plan is harness the microbial digestion in big silos. The silos are devoid of oxygen, which provides prime conditions for anaerobic digestion. Old food goes into the silo, and useful gas comes out. This biomethane gas can be used to generate electricity. "[J]ust like natural gas mined from the ground," explains Popular Science.
Sainsbury's already claims to be producing enough microbe-power to run the equivalent of 2,500 homes each year. To do this, waste from Sainbury's stores across the UK is being collected and used to power one specific store, in Cannock, England.
Though Europe is on the cutting edge of biomethane production, similar efforts are popping up in the US, Yale Environment 360 reports. In February, for instance, a waste management company in Los Angeles added food scraps from stores and restaurants to its energy-source portfolio.