Recycling, packaging and waste
Supermarket turning waste into watts
Green Ideas editorial team
Instead of sending its rotten unsold food to landfill, a US supermarket chain has started using it to generate electricity.
With over 300 stores in California, the Ralph’s supermarket chain has found it accumulates enough expired produce to power the equivalent of 2000 homes for a year.
The company has built a facility that grinds its waste into a fine pulp that is then fed into a sealed digester which breaks down the produce using bacteria and wastewater from a nearby dairy factory. The bacteria excrete methane gas, which is then clean-burned to power three turbines and generate electricity.
Once the waste is completely broken down the leftover sludge is sold to farmers for use as a nitrogen-rich compost.