"Without a network available to charge quickly, ownership of an electric vehicle is very limiting," Tesla spokeswoman Shanna Hendriks said. "By putting down the infrastructure for fast charging, it opens up the possibilities and the destinations that you can travel in an electric vehicle."
Still, experts say that for mass adoption of electric vehicles, charging time needs to be reduced to five to 10 minutes — the same amount of time it takes to fill up a tank of gasoline.
That will involve advancements in battery chemistry, software capability, charging infrastructure and electrical grid capacity.
"If I have to pull into a charging station and it takes six to eight hours, well, the debate's over — people will not buy that," Stogner said.
Drivers must have a garage
One significant limitation to electric-vehicle adoption is that many car buyers don't have a garage. Most apartment dwellers, for example, can't charge a car at home.
Shocket said it's a mistake to "assume everyone's got a garage with a plug in it."
Single-family homeowners are the most likely early adopters of electric vehicles. Auto companies are partnering with utilities and other groups to make it easier for car buyers to install special charging systems in their garages.
Utilities view electric vehicles as a new source of business. But they would have big problems if everyone immediately switched to electric vehicles and started charging during the day or during hot summer months, when electricity demand is at its highest.
That's why utilities are moving to encourage people to charge at night by offering cheaper electricity rates, said Hawk Asgeirsson, engineering manager for Michigan utility DTE Energy.
Grid managers also are coordinating with automakers and suppliers to allow consumers to use software applications that coordinate charging times with off-peak hours.
Asgeirsson said 85 percent of DTE customers who own electric vehicles are charging at night, when the electrical grid can easily handle the demand. DTE is studying EV electricity consumption "to see what's happening with customers' behavior," he said.