Two supermarkets are making lemonade out of lemons the green way—by converting their spoiled food into energy. Grocery chains Ralphs and Food 4 Less (both part of the Kroger Co.) have joined forces with FEED Resource Recovery to make use of the rotten and expired foods that their markets don’t sell. Any food that can’t be sold or donated will be transformed into energy to help run their distribution center in Compton.

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FEED Resource Recovery, a clean technology company, will be heading the project to convert the organic trash from each supermarket into energy by way of an anaerobic conversion system. Ralphs and Food 4 Less will collect spoiled, unsold food in containers and the food will then be put into a blending system to remove packaging, metal or glass, leaving just the organic material. The leftovers will then be mixed with wastewater from a neighboring creamery, creating the perfect consistency for the anaerobic digester—also known by FEED as “organic milkshake.”

Once fed into the anaerobic digester, the “milkshake” is converted into biogas, which is used to power microturbines and boilers. Leftover water is put through a purification process, and leftovers are transformed into fertilizer, leaving no waste throughout the whole process.

Kroger’s adopted FEED system processes 300,000 lbs of material per day, which not only reduces waste by 150 tons per day, but also produces 13 million kW of electricity. The clean energy produced could power 2,000 homes and accounts for 20% of the distribution center’s energy use.

+ FEED Resource Recovery