The landfill gas program at TEP, principal subsidiary of UniSource Energy, is in its seventh year of operation and works by taking methane gas from Tucson's Los Reales landfill and carrying it through a 5.6km pipeline to TEP's Sundt Generating Station, where the gas is burnt along with coal.
TEP claims that the landfill gas reduces the burning of additional coal to produce a cleaner burning fuel to provide reliable electricity to customers.
"This project has produced significant benefits for our community. We're capturing a naturally occurring fuel that otherwise would be wasted and turning it into clean, green energy for our customers," director of Remote Generation and Special Projects for TEP, Don Gin, said.
"TEP has generated up to 5.5MW of electricity in an hour from landfill gas, enough to serve about 5500 homes. By offsetting the use of coal, the system also reduces fossil fuel emissions from the Sundt Generating Station," Gin said.
Since the program began in August 1999, TEP claims that it has reduced sulfur dioxide emissions by more than 870 tons and avoided the production of more than 145,000 tons of carbon dioxide.
TEP says its landfill gas-to-energy program is the first of its kind for a commercial facility in Arizona and took four years to come into fruition.
"The use of methane gas, which is produced naturally through the decomposition process, is a key component of TEP's renewable energy program," Gin said.
"TEP generates more than 10.8 MW of power from solar, wind and biomass resources across Arizona.
"As long as we keep dumping trash in the Los Reales Landfill, the methane supply will increase yearly.
"The Los Reales landfill is expected to remain open for at least another 20 years," Gin said.
The company's performance monitor shows that the landfill gas burned during 2004 was able to compensate for the use of 14,388 tons of coal.
In 2005, the monitor shows that the burned landfill gas has prevented the use of 4403 tons of coal, which is claimed to relieve the environment of 6458 tons of CO2 and 39 tons of SO2.
