Sharp Grossmont Hospital is operating independently of the state power grid following completion of a taxpayer-funded energy plant.

The three-story, 18,400-square-foot plant in La Mesa houses an $18 million, natural gas-fired cogeneration plant producing up to 4.4 megawatts of electricity while also putting out steam that powers medical equipment, heats space and runs the hospital’s air-conditioning.

“Taxpayers can be assured that their publicly owned hospital is equipped to handle future energy capacity needs with on-site electric power generation at the lowest possible cost,” Michael Emerson, president of the public Grossmont Healthcare District, said in a Dec. 22 news release. “Even in the event of an outage or other emergency, the hospital will continue to operate as needed.”

The project was funded by Proposition G, the 2006 ballot measure that has also paid for a four-floor renovation of the 524-bed hospital’s East Tower. Money from the proposition is also covering construction of a 71,000-square-foot heart and vascular center.

San Diego-based Sharp HealthCare operates Sharp Grossmont under a lease with the district.