Last summer, as I drove around the San Francisco Peninsula, I caught glimpses of a sea change in American automobile culture. Plug-in electric vehicles and charging stations seemed to be everywhere. Near the entrance to Stanford University, I witnessed a three-car fender bender involving only electric cars. And perhaps most remarkable: the prevalence of the Tesla Motors Model S, a luxury electric sedan that’s become the new status symbol among the tech-savvy. With more than 90,000 built to date, the Model S is now a common sight on Bay Area highways and byways.