Juiced: Google&39's technical program manager for electric transportation, Rolf Schreiber, gets ready to charge a Nissan Leaf.

Count this as another perk of working for Google: free fuel for your electric car.

Google today said that it counts itself as the largest electric-vehicle charging station operator with about 200 chargers installed and another 250 ordered. The company's goal is to have 5 percent of its parking spaces equipped with electric-vehicle chargers, made available for free to Googlers.

"Our expanded charging system has already helped several Googlers decide to buy new EVs of their own, and we hope others will, too," wrote Rolf Schreiber, technical program manager for electric transportation at Google, in a company blog.

As it expands its current charging infrastructure, Google will be buying charge points supplied from Coulomb Technologies. These charge stations are networked and allow people to use Google Maps to find a free charge spot or make a reservation.

As part of its environmental sustainability initiatives, Google in 2007 purchased Toyota Priuses and Ford Escapes which are hybrids retrofitted with larger rechargeable batteries. Google now intends to expand that "Gfleet" to over 30 vehicles with the purchase of plug-in Chevy Volts and Nissan Leafs.

Employees can use Gfleet vehicles to get around campus or make errands. Between its plug-in car-sharing service and its biodiesel shuttle buses, Google estimates it's avoiding 14 million vehicle miles, or 5,400 metric tons of carbon dioxide a year.

Fleet operators are critical to the adoption of plug-in electric passenger cars as buyers and providers of car charge points. Plug-in cars cost substantially more upfront than gasoline-only cars but fleet operators are more likely to consider the operating savings from using electricity as a fuel, rather than gas or diesel. Alternative-fuel vehicles can also be a visible way to demonstrate corporate sustainability efforts.

Google has a number of green initiatives, including bets on renewable-energy companies and investments in solar and wind projects. Expanding its fleet is part of its program to promote green technology and practices, said Rick Needham, director of green business operations. "We hope other companies will take a look at these technologies and figure out how they can incorporate them into their own operations," he said.