The Skunk Creek Landfill [right, credit Phoenix.gov] in Phoenix will supply enough methane gas produced from decaying garbage to generate 30,000 megawatt-hours of power. The power will go to Pasadena, California under a 20-year contract and is about enough to supply about 5,000 homes according to local officials.
The cost of the methane power will be about $550,000 more than non-renewable energy but is part of that city's green goals.