Los Reales Landfill

Using methane gas to generate electricity

TEP takes methane gas from the Los Reales Landfill in Tucson and burns it in place of coal or natural gas to produce electricity. Methane gas from the Los Reales Landfill is piped 3.5 miles to TEP's H. Wilson Sundt Generating Station to co-fire a boiler that supplies electricity to our customers. Methane gas is a byproduct of decay in landfills, and it could contribute to global warming.

Methane Gas

  • TEP derives energy from landfill gas which helps offset conventional energy production. Over the course of a year, the project can generate enough power to meet the annual electric needs of up to 2500 homes.
  • This project is Arizona's first commercial facility fueled by landfill gas. It allows TEP to replace up to 13,000 tons of coal per year, thereby achieving additional carbon dioxide emissions reductions.
  • The Los Reales Landfill Gas-to-Energy Project was officially launched August 15, 1999. Completion of this project took four years, from the beginning of contract negotiations through permitting, engineering, procurement and construction.
  • From August 1999 through May 2010, the system has reduced sulfur dioxide emissions by more than 1,257 tons while avoiding the production of more than 239,159 tons of carbon dioxide.
  • During the first five months of 2010, the use of landfill gas has allowed TEP to avoid burning 4,147 tons of coal. TEP was able to reduce sulfur dioxide emissions by more than 32 tons and avoid the production of more than 9,000 tons of carbon dioxide.
  • As long as we keep dumping trash in the Los Reales Landfill, the facility will continue to produce methane. The Los Reales Landfill is expected to remain open for at least another 20 years.
  • Energy output varies from year to year depending on methane production, which itself depends on moisture levels in the landfill and other factors.
  • The project's environmental benefits vary depending on whether the methane gas is being used to offset the use of coal or natural gas. While coal is typically used to fuel the generator in which methane is used, TEP used natural gas to fuel that unit through much of 2009


  • A cleaner environment. Using methane for fuel produces less carbon dioxide and sulfur dioxide than burning coal or natural gas, the two fuels it has offset at TEP's H. Wilson Sundt Generating Station.
  • Safer air. The program makes use of a hazardous byproduct of decay that otherwise would have to be captured and burned off without benefit.
  • Increased public revenue. TEP pays the city of Tucson $500,000 a year for the rights to gas from its Los Reales Landfill, subsidizing other public projects while helping the city meet its obligation to cap methane emissions.