New York Is Turning Its Leftovers Into Natural Gas, With the Help of Hungry Bacteria
Some cities are taking table scraps and turning them into fuel.
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In Brooklyn, huge tanks filled with bacteria wait for the first food scraps to start arriving. These "digester eggs" are here to solve an eternal conundrum: what to do with the scraps of food left behind during cooking or rejected on the plate? When food waste goes to landfills, it takes up space and produces climate-disrupting greenhouse gas. But New York City is adopting a new idea: make gas out of food waste on purpose, and use it to fuel the city.
Where others see foul and potentially hazardous sludge, Pynn sees a source of renewable energy, thanks to trillions of helpful bacteria inside the digester eggs.
"The digesters like to be fed like us: three times a day," he says. "They like to be kept warm, 98 degrees. And whether we want to admit it or not, we all make gas. And that's what we have these guys for: to make gas."
In this case, that gas is methane, which can be used to heat homes or make electricity. Right now, what these bacteria are digesting is mostly sewage sludge. But they're being introduced to a new diet: food scraps. The hope is that this plant will soon take in hundreds of tons of organic waste from houses and apartments.
In 2015, New York City restaurants will be required to separate their organic waste from the rest of the refuse. Some have already started as a part of former Mayor Michael Bloomberg’s Food Waste Challenge initiative, and, in the first six months of the program, participating restaurants diverted 2,500 tons of waste from landfills. They turned that waste into compost or delivered it to facilities like the one in Brooklyn, to be turned into biogas, and from there into electricity.
But there's a difference between recycling at a business and recycling at home. The city is working to expand the food waste recycling programs to encompass residential food waste as well, collecting food scraps in the same way that bottles, cans and other recyclables are collected now.
Residents of apartment buildings dump pails of food scraps at central collection points, most likely in the same places they put recyclable material.
It remains to be seen whether New Yorkers will embrace the program, given that some may cringe at keeping a container of potentially malodorous waste in a typically cramped urban kitchen, even if it is supposed to be emptied regularly.
The city has historically had a relatively mediocre record in recycling, diverting only about 15 percent of its total residential waste away from landfills.
Even if New Yorkers take to the new recycling program with enthusiasm (and at least some will, as seen in the popularity of the Greenmarket composting program), there’s the problem of where all that rotting food will go. The plant in Brooklyn isn’t built to handle every single last scrap of potato peel that New York City's kitchens turn out.