Alameda County residents can now charge their electric vehicles for free -- at least until the end of 2014 -- at county-owned parking garages, lots and buildings in Oakland, Hayward, Alameda and San Leandro.

The pilot program offers 40 stations in all, with 36 stations open to the public during regular business hours starting Tuesdaywith the garage at 585 Seventh St., and Thursday at the AlcoPark Garage, 165 13th St. in Oakland.

Stations are already running in Hayward at the Amador Parking Garage, 24360 Amador St., and Public Works Building, 224 West Winton Ave. Drivers can also power up at the county's Environmental Health Building, 1131 Harbor Bay Parkway, in Alameda and at the Juvenile Justice Center, 2200 Fairmont Dr., in San Leandro. Encouraging more people to drive electric and hybrid vehicles is one of the county's strategies to limit greenhouse gas emissions. Drivers have to pay to enter the parking garages but the stations are free until at least December 2014, when the county will decide whether the Board of Supervisors should make motorists pay at the electricity pump.