National Geographic : 2009 Nov
ART: EBOY. SOURCES: ART JAMES, OREGON DEPARTMENT OF TRANSPORTATION; TIM LIPMAN, UNIVERSITY OF CALIFORNIA, BERKELEY; RICHARD LOWENTHAL, COULOMB TECHNOLOGIES; BRIAN PURCHIA, OFFICE OF THE MAYOR, SAN FRANCISCO Bob, like most commuters, charges his car at home overnight. His "smart meter" automatically starts the process when rates go down and stops when the battery is full. A charging station at the office allows him to top off. Sonia's "neighborhood car" goes just 20 miles on a full charge, but a dashboard computer locates available charging outlets and alerts her if the power company shuts them down to meet high demand elsewhere. Justin takes his sports car on road trips. Filling up on the highway may mean pulling into a robotic battery-switching station or plugging into a high-voltage charger that fills the battery in 20 minutes or so. GREEN POWER Electric cars will be clean only when their power source is; most electricity today comes from fossil fuels.