San Francisco restaurants are often on the cutting edge of sustainability and green practices. They’ve pioneered ways to turn food waste into fertilizer, reduce food miles by sourcing locally, and decrease waste through recycling and composting.
More recently, the East Bay Municipal Utility District has started converting up to 200 tons of food waste gathered from area restaurants into electricity every week, and that power is used in some of the very same restaurants that contribute their organic waste.
The waste is converted by allowing it to be broken down by bacteria in a gigantic underground tank. This process gives off methane, which is then burned to heat water and create steam, which drives a turbine that creates electricity. This is the same process used by most coal fired power plants, except the fuel in this case is sustainable.
Currently food scraps make up a small portion of the organic waste that is processed at the East Bay facility. The majority comes from the wastewater treatment plant onsite and several large-scale local industries like vineyards and dairies. But 30 million tons of food scraps are sent to landfills each year, which makes up more than 20% of all landfill waste.
That means there’s a lot of room for improvement. The best part about the process is that a rich fertilizer is the byproduct of breaking down all that waste, which can help local organic farms that supply restaurants. The primary obstacle to wider adoption of organic electricity is a lack of processing plants. That could change rapidly in the next ten years as sustainable electricity gains more momentum in the American economy.
The restaurants participating in the food scrap collection program did have to put some extra time into training employees to keep contaminants like plastic and other foreign object out of the bin destined to be converted into electricity. Despite the extra training, the savings in reduced garbage production was enough to help some restaurants save money, since the scraps are collected for free.
Only a tiny fraction of the food waste produced in the Bay Area goes to the organic generator run by the East Bay Municipal Utility District. The room for growth is enormous, and if San Francisco could collect almost all of the 1,800 tons of waste produced every day by area businesses, that would be enough electricity to power 25,000 homes. That’s a serious contribution San Francisco restaurants can make to the local power grid.