File photo of a Chevrolet Volt electric vehicle plugged into a charging station during a news conference in Rochester Hills

 
File photo of a Chevrolet Volt electric vehicle plugged into a charging station during a news conference in Rochester Hills
A Chevrolet Volt electric vehicle is plugged into a charging station at Sunlogics new manufacturing center in Rochester Hills, Michigan in this file photo taken July 28, 2011. General Motors Co will temporarily halt production of its Chevrolet Volt plug-in hybrid and lay off 1,300 workers for five weeks this spring, a spokesman said on March 2, 2012. Workers are expected to return to work on April 23. Picture taken July 28, 2011. REUTERS/Rebecca Cook/Files (UNITED STATES - Tags: TRANSPORT BUSINESS EMPLOYMENT)