One of the most compelling arguments against all Plug-In Electric Vehicles is the local grids ability to handle to extra load. With only a few, there shouldn't be a problem, but as more people begin to transition to plug in type vehicles, the demand for power will sky rocket with no real way to supplement it. To combat this problem, Ford has developed a system that will actually talk to the local grid while plugged in.
The system is basically a way for an owner to program the charging components of their vehicle and be able to walk away without worry. The driver can choose how the vehicle is charged, such as a slow charge or a quick charge, and when the charging will begin and end. It will also be able to charge to a specific percentage and then hold that charge until the vehicle is unplugged.
Alongside the ability to customize the charging cycle of a vehicle, the system will also allow for multiple vehicles to draw from the grid without overloading it. This will be accomplished by limiting the amount of power being pushed to the individual vehicles while maintaining a constant flow overall.
The system is being tested and could see production as early as 2011. Auto Blog