Major EV Hurdle: Overnight Parking

Everyone knows that high cost and limited range are big challenges limit the appeal of electric vehicles. But a bigger barrier to widespread acceptance, at least in the U.S., may a shortage of places to charge them overnight, according to researchers at Carnegie Mellon University.

The problem, they say, is that most EV charging will be done at home, not at public-use facilities.

The researchers estimate only about 40% of American households offer the necessary combination of an owned residence with dedicated off-street parking in a location suitable for installing a charger. Apartment buildings, for example, don't meet those criteria.

The researchers also point out that many households have more cars than dedicated parking places for them. That means the actual proportion of the U.S. car fleet that could easily to converted to electric power is well under 40%.

The Carnegie Mellon team acknowledges that many households are able to switch at least one of their vehicles to electric power now. But it says the hope of EV proponents that electrics will account for more than half the U.S. car fleet isn't likely to be met without massive changes in America's approach to parking and charging such vehicles.