Electric vehicle (EV) charging stations went live outside San Francisco's City Hall this week as the mayor vowed that the area will lead the nation in steering away from gasoline-powered cars.

"Our goal is to transform the Bay Area into the EV capital of the United States, and a networked infrastructure is essential for the adoption of electric vehicles," said mayor Gavin Newsom.

"San Francisco is proud to be the first city to feature charging stations with technology to support our city's clean electric fleet vehicles and car-share fleets."

Coulomb Technologies installed three charging stations unveiled Wednesday at a plaza across from the City Hall entrance.

The ChargePoint Network stations are part of a two-year public demonstration of the feasibility of using electric vehicles in cities.

Stations feature Fleet Management Portal technology that tracks amounts of gasoline saved and greenhouse gas emissions avoided by each electric vehicle.

The system sends text messages to drivers' mobile telephones alerting them when electric vehicles need charging, or when ones that are parked have finished being charged.

"The Bay Area is the epicenter of the electric vehicle movement," said Coulomb chief executive Richard Lowenthal.

"A smart, networked infrastructure is an essential enabler of this movement and the City of San Francisco is leading by example."

Coulomb is based in the California city of Campbell and specializes in plug-in vehicle charging infrastructure.