Wastewater Plant to Replace Fossil Fuels With Grease

Oct. 16, 2006

The wastewater treatment plant in Millbrae, Cailf., plans to replace fossil fuels with grease.

Leftover cooking grease from Bay Area restaurants will allow the plant to provide for 80% of its own power. This method will save taxpayers money and cut down fossil fuel emissions. The city hopes to have the plan in place by the end of the month.

The plant will receive a $5.5 million upgrade, which will include the addition of a receiving dock for trucks to unload 3,000 gallons of grease a day. Microorganisms in the facility's existing solid-waste digester will eat their way through the grease, significantly boosting the amount of methane the plant uses to power its generators.

According to Mercury News, the plant already generates 40 to 50 percent of its own power by trapping the methane and carbon dioxide gases that are byproducts of the waste breakdown process. The gases enter a combustion engine that in turn powers the generator, creating electricity.

The upgraded technology, designed and installed by a subsidiary of oil giant Chevron, also adds a 250-kilowatt microturbine generator capable of putting out enough energy to survive an outage.

The city stands to gain $366,000 a year in energy savings and earn some money on ``tipping fees'' from grease haulers, who will pay the plant 10 cents a gallon or more for the privilege of disposing their waste.

Officials estimate that Millbrae would earn enough on its treatment plant upgrades to recoup its expenses in 20 years.

Source: Mercury News