Someday soon, your half-eaten bagels and the forgotten bin of strawberries at the back of your refrigerator may find a second life as a source of heat, at least if you live in New York City. In a new pilot program, New York is collecting food waste and trucking it to a wastewater treatment plant in Brooklyn, where it will eventually be generating enough heat for more than 5,000 homes.
The wastewater treatment plant already produces some energy. Biogas produced during the treatment process helps power the plant itself, though right now, the excess is flared into the atmosphere—not a great idea since methane is a potent greenhouse gas.
Now, the city’s Department of Environmental Protection is hooking up with a local utility to capture that extra gas. And by adding food waste to the mix, they’ll be able to generate more natural gas energy and keep New Yorkers toasty in the winter.
The program will start by collecting food waste from school cafeterias, since the public school system has a reliable and steady supply of trash (blame the terrible lunches). Eventually, the plant will be able to process around 500 tons of food waste per day, which represents about 15% of the organic trash in the city. The rest will be composted.
While composting is obviously much better than just sending food straight to landfills, generating heat goes a step farther. "[It] captures the tremendous energy value rooted in the organic waste," says Rachel Amar from Waste Management, the company coordinating the collection of all of the trash.
In all, the project can remove more than 90,000 metric tons of emissions a year. One part of that is due to the fact that garbage trucks can eliminate 2.1 million miles of trips. If the project can expand, it will obviously have an even bigger impact on transportation.
"Since organic material makes up approximately 30% of the waste stream, recovering food waste for biogas production can enable municipalities to significantly reduce the amount of material sent to landfills," says Amar.
If the project is successful, the city hopes to roll it out to other wastewater treatment plants as well.
Turning food to heat is not really a panacea for the food waste problem. As we’ve written before, Americans waste a ridiculous amount of food, and it’s not just a landfill issue. Growing, transporting, and processing food takes huge chunks of energy. But until we manage to stop throwing things out, this is a good way to get a little more out of our leftovers.