Ready for a shocking fact? Forty percent of food produced in the United States each year is never eaten. Yes, you read that right—40 percent. We’re talking about expired meat, blemished, overripe fruit and moldy bread. Sure, some food is donated to food pantries and other charitable organizations. Yet, the Natural Resources Defense Council reports that 40 percent of food in the United States—about 20 pounds of food per person per month, or the equivalent of $165 billion annually—goes uneaten.
In her May 2013 Los Angeles Times article, “A powerful use for spoiled food,” Tiffany Hsu details one retailer’s solution: at a massive distribution center in Compton, Calif., Kroger Co. converts 150 tons of unsold food a day into energy. Thirteen million kilowatt-hours of electricity a year, to be precise—a figure Kroger says could power more than 2,000 California homes a year.
The technology used to transform stale food into clean electricity is called an anaerobic digester system. Rather than sending food they cannot sell or donate to a landfill, Kroger subsidiaries Ralphs and Food 4 Less ship their unusable food to the anaerobic digester facility. Expired food, along with its cardboard and plastic packaging, is shredded in an enormous grinder, pulverized in a pulping machine, and eventually stored in a two million gallon silo. Here, bacteria convert the sludgy former food into methane gas, which is siphoned from the tank to power three on-site turbine engines. Meanwhile, the anaerobic digester’s excess water is purified and sent into the industrial sewer system, while excess sludge is used as fertilizer. The system offsets more than 20 percent of the distribution center’s total energy demands, and does not produce any offensive odors.
Kroger estimates the anaerobic digester will offer an 18.5 percent return on the company’s investment. Over its lifetime, the project could save the grocer $110 million. Anaerobic digesters are also being considered as a potential fuel source for data centers, farms, and government buildings, to name a few.
On the surface, this all seems like a great idea. Kroger’s anaerobic digester is an ingenious method of dealing with food waste that not only reduces the company’s electricity bills, but also helps the environment. But, this fascinating process also raises a multitude of questions: why are supermarkets wasting so much food in the first place? Should we be producing less? What can retailers do to get food off their shelves before it’s too late?
Food waste is a major problem. Considering the exorbitant amounts of land, water, labor and money it takes to create our food in the first place, throwing away so much of it—even to produce clean energy —can’t be the best way. Kroger’s anaerobic digester is a practical, economical, way of handling the issue, but what we really need is a solution that reduces food waste from the beginning. Maybe perishable goods should be discounted to correspond with freshness, with prices dropping as expiration dates near. Or maybe Andronico’s is onto something: the Northern California chain sells produce that is aesthetically damaged but still edible at a discount. Maybe food should be donated sooner to avoid missing the freshness window.
What do you think? Are anaerobic digesters the wave of the future, or should we determine a way to not waste so much food? Share your thoughts in the comments section below!