SUISUN CITY -- Methane gas from the Potrero Hills landfill will soon be used to fuel state-of-the-art engines producing 9.6 megawatts of green, renewable electric power. This gas would otherwise be wasted and burned in the landfill flare or released into the atmosphere.
[caption id="attachment_59066" align="alignright" width="405" caption="Six Caterpillar 3520 methane gas-powered generators will be used at the Potrero Hills Landfill to produce green electricity."][/caption]
The power potential is equivalent to eliminating greenhouse gas emissions from the consumption of 40 million gallons of gasoline, or emissions from 1,900 railcars of coal. (Gas produces 52 percent fewer emissions than coal.)
The Potrero Hills Landfill has entered into a 25-year contractual agreement with Potrero Hills Energy Producers, LLC, (DTE Biomass Energy Inc.) to develop a power plant.
The landfill produces an estimated 3,500 standard cubic feet of methane gas per minute, enough to fuel six Caterpillar (CAT 3520 gas generator) engines, each producing 1.6 MW of power that will be installed at the site.
Electricity generated by the plant will be carried to the PG&E grid six to seven miles away, depending on the route selected, and some underground utility connections will be used to reduce the visual impact.
The new facility will also be located more than half a mile from the nearest residence behind an existing ridgeline. The plant stacks will not be visible behind the ridgeline and all machinery will be housed in containers or buildings, reducing sound levels to points at or below permitted limits.
"This form of clean energy provides a baseload power supply unlike wind and solar, since our plant will operate 24-hours a day -- even when there is no wind or daylight," said James Dunbar, District Manager for the Potrero Hills Landfill.
"We expect to break ground for this installation in the first quarter of 2013 with full commercial operation expected six to nine months later."
All power produced will be sold to PG&E. The landfill will benefit from this project by receiving reduced power rates for its role in developing sustainable power.
The Potrero Hills Landfill was opened in 1986. Only 190 acres of the original 1,400-acre parcel were used as a landfill until 2012, when the landfill area was expanded to 340 acres. This expansion assures that enough landfill gas will be available for the 25-year life of the project.
"The $20 million investment by DTE represents a long-term solution designed to operate as long as there is a sufficient supply of landfill gas," said Michael Kotyk, vice president, business development, with DTE Biomass Energy, Inc.
"Estimates show that at the current rate of fill, the Potrero Hills landfill should be able to operate for another 35 to 40 years. Even after it is eventually closed, the decomposition of garbage will continue to produce gas for an additional 20 years."
According to Mr. Dunbar, "As the landfill grows, methane production will rise steadily, producing good green energy for generations to come."
This landfill is located 1.5 miles south of Travis Air Force Base, south of Highway 12 and 1.5 miles east of Suison City.
There are more than 200 landfills in California and only about 20 of these currently have sustainable methane recovery systems.
"A key requirement is that the landfill must be of a certain size to produce enough gas to make such systems economically viable," Mr. Dunbar said.