Trash May Be (Energy) Treasure Trove

Earlier this month, a New York Times article highlighted the fact that European countries are burning garbage as a renewable source of energy – but that similar efforts in the United States are lagging behind. The article cites a 2009 study which “came down strongly in favor of waste-to-energy (WTE) plants over landfills as the most environmentally friendly destination for urban waste that cannot be recycled.” I was curious about the research itself, and set out to learn a little more about it.

The study, “Is It Better To Burn or Bury Waste for Clean Electricity Generation?,” was published in 2009 by Environmental Science & Technology, and was co-authored by NC State University’s Dr. Joe DeCarolis, with Ozge Kaplan and Susan Thorneloe from the U.S. Environmental Protection Agency.

The researchers had set out to determine the potential greenhouse gas impact of two alternative energy sources: WTE and landfill-gas-to-energy (LFGTE). WTE is when municipal solid waste (i.e., garbage) is incinerated to create electricity. LFGTE is when you dump garbage in a landfill, wait for it to produce methane, and then use that methane to create electricity.

“The bottom line is that the study indicates WTE produces significantly less greenhouse gas than LFGTE, and appears to compare favorably to coal,” says DeCarolis. (I would also observe that we’re making lots of garbage every day, and the supply of easily accessible coal is not infinite – but the research doesn’t go into that.)

Stay tuned for future developments in this area. DeCarolis is working with NC State’s Dr. Morton Barlaz to analyze additional data on carbon sequestration at landfills. Their findings may affect current calculations on the attractiveness of LFGTE as an option for addressing greenhouse gas concerns.