AUDIE CORNISH, HOST:
It takes a lot of energy to produce the food we eat, and new technologies are beginning to give some of that energy back to us. Europe has been extracting natural gas from organic waste for about a decade. And as Dan Boyce of member station KUNC reports, this is starting to pick up in the U.S.
DAN BOYCE, BYLINE: If you can picture 8 million gallons of what people have flushed down their toilets, that's what I'm smelling right now.
DAN TONELLO: Yeah, there's - it does put off an odor.
BOYCE: That's Dan Tonello, manager of Grand Junction Colorado's Wastewater Treatment Plant. We're staring down at a brown torrent of flowing raw sewage. And the odor - it's starting to smell more like money to Tonello. Processing the sewage produces a lot of methane, which the plant used to just burn off into the air.
TONELLO: Not good for the environment and a waste of a wonderful resource.
BOYCE: Yet with more infrastructure to further refine it...
(SOUNDBITE OF TRUCK STARTING)
BOYCE: ...You get natural gas, chemically identical to what's drilled from underground. Grand Junction has been replacing an aging fleet of garbage trucks and buses with natural-gas vehicles, fueled mostly by the human-sourced gas from the treatment plant. Tonello says Grand Junction is the first city in the nation to do that.
TONELLO: We're looking at hundreds of thousands of dollars a year being saved by implementing this process.
JOANNA UNDERWOOD: That's a model for small wastewater treatment plants anywhere in the country.
BOYCE: Joanna Underwood is the president of Energy Vision, a nonprofit dedicated to expanding the use of this renewable natural gas. It's cleaner than diesel fuel and puts emissions that were heading for the atmosphere anyway to good use. And there are other sources beyond human waste. I met Underwood in the ground-floor restaurant of a Denver hotel, and she started walking among the tables pointing them out.
UNDERWOOD: You're looking at people eating ham and toast and eggs - all of this is organic.
BOYCE: Natural gas from food waste. Right now, food scraps from restaurants are being collected along with that from grocery stores and large food manufacturers all over Colorado's densely-populated front range. In just a few weeks, it will all be heading up to northern Colorado. The Heartland Biogas Facility is in its final stages of construction. It basically does the same thing the plant in Grand Junction does but on a much bigger scale, an enormous scale.
BOB YOST: It's one of the largest in North America.
BOYCE: Bob Yost's company A1 Organics is partnering with the facility to coordinate the delivery of all that food.
YOST: There could be 25, 30 semi loads per day of food waste coming in and then the manure is added to that.
BOYCE: Manure from a local dairy. Yost says the best way to get the most natural gas from waste is for your facility to have a balanced diet of both food scraps and manure.
YOST: After they've created the renewable natural gas, it's injected into the pipeline and then it's delivered to anywhere in the country.
BOYCE: The same pipelines used for fossil fuel natural gas. Joanna Underwood of Energy Vision - she says if all the organic waste in the country were gathered, current technologies could produce enough natural gas to replace about half of the diesel fuel used in U.S. transportation.
UNDERWOOD: For this sector, which in and of itself is big, it's not a small piece.
BOYCE: So not a replacement for the traditional oil and gas industry by a long shot. But Underwood argues practical solutions to climate change have to be assembled piece by piece. For NPR News, I'm Dan Boyce in Denver.
CORNISH: This story comes to us from Inside Energy, a public media collaboration focusing on America's energy issues.