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For the Municipal Water/Wastewater Industry

Switchgear from Eaton is helping a municipal wastewater treatment facility in Millbrae, Calif., turn grease into green, and saving the city more than $300,000 per year in the process.

The project began in 1994, when the public works department of Millbrae, a community of 20,000 just north of San Francisco, invested $5.3 million in becoming the first municipal wastewater plant in North America to generate 80 percent of its own energy.

Partnering with Chevron Energy Solutions, the Millbrae facility developed an innovative system that converts a 3,000-pound daily delivery of restaurant grease into naturally occurring methane gas. The methane gas then fuels a 250-KW microturbine cogenerator that produces electricity for wastewater treatment. The excess heat generated by this process is also used to power the digester tanks that convert the restaurant grease into methane.

Critical to this entire process is a paralleling switchboard developed by Eaton. Working closely with Chevron Energy Solutions, Eaton created a switchboard design that incorporates Magnum breakers, an IQ transfer, a molded case circuit breaker, and an IQ analyzer to monitor power distribution.

This switchboard gear functions as the nerve center of the facility, controlling all three of its available power resources - the methane-powered microturbines, the local utility and the back-up generator.

Eaton also supplied a motor control center, equipped with full-voltage non-reversing starters and a variable frequency drive, that meets NEMA 3R specifications.

Thanks to these technological innovations from Eaton and Chevron Energy Solutions. The Millbrae plant harvest enough biogas to generate approximately 1.7 million kilowatt hours of electricity each year, independent of the local utility. This has nearly doubled the amount of green power produced at the plant, reducing carbon emissions by 1.2 million pounds per year, which is equivalent to the CO2 absorbed by 170 acres of trees.

Better still, the use of renewable energy has produced revenues and savings of more than $335,000 per year for the city of Millbrae, enough to fund the entire cost of the project, including maintenance costs.

To learn about green energy solution from Eaton for your municipal water and wastewater treatment facilities, we invite you to contact Eaton Canada.