Air Date: Week of October 27, 1995
In Los Angeles lies a landfill project that takes noxious greenhouse methane gas and harnesses it to create safe usable energy. Stephanie O'Neill reports from L.A. on the uses of this emerging technology.
CURWOOD: There's plenty of energy in garbage. In the past, cities and towns burned trash, and used the heat to generate electricity. But that process tends to pollute. But there is another way to harness the energy of trash: garbage decomposing in landfills gives off methane gas. And this can be trapped and burned with very little pollution. Currently, methane gas from most landfills is now simply escaping into the atmosphere and adding to urban smog and the greenhouse effect. Now the US Environmental Protection Agency is urging dump operators to capture methane and put it to work, a move which also helps to clean up the air. Stephanie O'Neill reports from Los Angeles.
O'NEILL: More than 2,000 trucks, each piled high with a colorful and pungent assortment of garbage, dump their load in a crater-like pit here at the Puente Hills Landfill in Whittier, about 15 miles east of downtown Los Angeles. Within minutes, yellow tractors spread the trash in huge earth scrapers covered up with a layer of clean dirt.
COSULICH: They keep what they call the open face area very small. So even though we're sitting here right next to it, there's no seagulls, there's no odors.
O'NEILL: John Cosulich is a supervising engineer with the Los Angeles County Sanitation District, which operates the Puente Hills facility.
COSULICH: The refuse, once it's landfilled, it undergoes a natural biological decomposition process. It results in a natural gas. It's the same way natural gas is formed. We just beat the oil companies by a few million years.
O'NEILL: About half of the gas produced at this and other landfills nationwide is highly-polluting methane, which is 20 times more potent than carbon dioxide and one of the main causes of global warming. Left alone, methane seeps from landfills and into the air, but since the early 80s operators of the Puente Hills facility have captured the gas and turned it into energy.
COSULICH: We have one of the most successful landfill gas to energy facilities in the world here. It's 50 megawatts, it generates enough power for almost 100,000 homes.
O'NEILL: What's more, the profit from the electricity sales is used to lower disposal fees for nearby residents. These benefits of landfill mining are among those touted by the Environmental Protection Agency, which is hoping to encourage landfills nationwide to follow the Puente Hills lead. Right now, only about 140 landfills in the US turn their gas to energy. But Cindy Jacobs, head of the EPA's methane outreach program, says many more could follow suit.
JACOBS: We estimate that there are about 750 landfills out there that could economically recover their landfill gas for energy. If the full 750 were to turn that landfill gas into electricity, that would be enough energy to power 3 million homes.
O'NEILL: The EPA has recently imposed strict methane emissions standards on landfills after studies showed them to be among the largest source of human-produced methane. The new regulations require landfill operators either to burn the gas as it escapes, which produces less polluting carbon dioxide, or to collect it for energy. Christopher Flavin is vice president for research at the World Watch Institute, a nonprofit research organization based in Washington, DC.
FLAVIN: One of the convenient things about it is that it's generally found near cities, which is where we need electricity. So it's an important supplementary source of energy.
O'NEILL: Moreover, Flavin says, as power plant technology advances the gas to energy option will become an economically viable choice for even the smallest landfills.
FLAVIN: One of the things that's going on in the power industry is that much smaller scale generation is becoming economical. The average size of a new power plant has declined dramatically in the last few years. And I think there are some new technologies coming along, like, you know, very small gas turbines and fuel cells that could make this an economical resource.
O'NEILL: At Puente Hills, 60 miles of dark green pipes carry the methane to the power plant where it's converted to electricity and then sold to the local utility company. The rest goes either to fueling county vehicles at on-site gas pumps, or is piped directly from the landfill to a nearby college where it's used for heating. Cosulich says while smaller dump sites that can't afford today's power plants await technological advances, this so-called direct use of landfill methane lends itself well to their operations.
COSULICH: It's a very viable technology for some of the smaller sites, where it's not really cost-effective to build an entire power plant. You can just put it in a pipeline a mile away to a large industrial user. And that is a common way of doing it and a very cost effective way.
O'NEILL: Another plus, John Cosulich says, is landfill gas is truly a renewable energy source that may prove one generation's trash can become another's treasure. For Living on Earth, I'm Stephanie O'Neill in Los Angeles.
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