California-based Pacific Gas and Electric Co. and General Motors Co. said Tuesday they are launching a pilot program to use the automaker’s electric vehicles as on-demand power sources for homes in the utility’s service area. The companies said they will test vehicles with “bidirectional charging technology that can help safely power the essential needs of a properly equipped home.” They expect to test the first vehicle-to-home capable EV by this summer. To make this possible, GM and PG&E will use the bidirectional hardware and software that will enable power to flow from a charged EV into a c…