In a slew of announcements this week, a picture of what the future of plug-in vehicle charging might look like is starting to emerge.

The Problem:

There are 54 million garages for the 247 million registered cars in the US, meaning that the majority of cars are parked overnight in parking structures, parking lots or curbside.

As a result, most potential plug-in vehicle consumers do not have an adequate place to charge their vehicles. This problem is even more pronounced in urban areas like San Francisco, where only about 16% of cars are parked in garages overnight and the rest end up curbside or in parking lots.

Also, although the US power grid probably has enough overall capacity to supply energy to a nation of plug-in vehicles, it may not have the ability to charge them when they all plug-in and demand energy at the same time — say 6 pm every weekday.

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