Trash Gas to Juice
City councilors aim to convert local landfill gas to electricity
It’s pretty easy to ignore trash. You throw it in the dumpster, leave it in a container alongside the curb, a truck picks it up and shoots it off to the landfill. Few think ever again about that trash rotting in a landfill; even fewer consider the gas coming off those landfills. The fumes are mostly methane gas, but also carbon dioxide, organic compounds such as nitrogen and sulfur, and toxic chemicals such as benzene and vinyl chloride.
Left alone, landfills release tons of methane and carbon dioxide into the atmosphere. The nation’s more than 3,000 municipal landfills are actually responsible for about 25 percent of the human-released methane released into the atmosphere; in other words, landfills are a pretty major contributor to global warming.
Now, City Councilor Isaac Benton and Council President Martin Heinrich are hoping to put that methane to better use. The two councilmen, in cooperation with the city administration, plan to find a way to convert those gases into electricity.
Albuquerque has three landfills, though two, the Los Angeles and Eubank landfills, are now closed. (“Closed” means full, by the way; not inactive.) At the Cerro Colorado landfill on the Southwest Mesa about 20 miles from Downtown the city currently captures about 17 percent of the gas off that landfill and, using a microturbine, converts it into electricity. The rest is sucked out of the center of the landfill and “flared.”
According to the U.S. Environmental Protection Agency, there are about 300 landfills nationwide generating electricity from landfill gas. Were the city to capture the remaining 83 percent of the Cerro Colorado’s gas, instead of just burning the emissions, the city could generate electricity on-site. The city could also sell the excess electricity to PNM. That also helps PNM, since landfill gas projects qualify under the state’s renewable portfolio standard. That law, passed in 2004, requires that by 2011, 10 percent of the energy provided by all investor-owned utilities, such as PNM, be from renewable sources.
Benton is particularly excited that the project could be used to generate alternative fuels for vehicles. Natural gas is very clean burning, he says, and there will certainly be a market for it: “I’m anticipating, in the future, that the cost of electricity will go up more slowly than the cost of vehicle fuel.”
Whatever ends up happening to the gas, there are better uses for it than just shooting it off into the air: “We can’t be wasting energy anymore,” says Heinrich. “We’re flaring off methane; that’s a lot of carbon going into the air, with zero of that being used for generation--that’s not a wise use of resources.”