BERLIN, GERMANY - MARCH 15:  An electric car charger logo is seen on a car charger at the Electric Mobility Week (e-Mobilitaetswochen), a public Volkswagen (VW) event at the former Tempelhof airport, on March 15, 2014 in Berlin, Germany. The event was designed to promote the company's e-Golf und e-up! automobiles, as well as its other alternative energy powered vehicles.  (Photo by Adam Berry/Getty Images)