According to researchers at the Swiss Federal Institute of Technology in Lausanne (EPFL), if electric vehicles grow in prevalence and charging speed increases to compete with gas-powered vehicles, we're going to wreck the grid. EPFL's team believes it has a solution, based on something we're already using.
It's called buffer storage, and it's essentially similar to underground gasoline tanks that gas stations currently use. Instead of charging a car by drawing power directly from the grid, it would rely on juice stored off-grid, just like how we don't pull gasoline from a central line that runs through an entire town.
The "storage tanks" themselves wouldn't kill the grid, either, because they would be charging constantly at a lower power level. The capacity would theoretically be high enough to mitigate any chance of total depletion.
This idea is a little cart-before-horse, if only because charging times are not yet approaching the speed -- and adoption is not yet approaching the rate -- where many users charging at once would put unreasonable stress on the grid. But, as more automakers tout the viability of electric vehicles, and as charging technology advances, it will eventually become a concern.
EPFL also created a formula that will help future charging-station owners figure out how much storage they'll need, incorporating parameters like traffic statistics and battery charge capacity.
This isn't the only conceivable solution to this future threat. Last year, a San Francisco organization erected solar-powered EV charging stations that were also off-grid. They can only hold about 100 miles' worth of charge (22.5 kilowatt-hours) and aren't lightning-fast (Level 2 charging, which adds roughly 10 miles of range per hour of charge), but it's another important step in attempting to keep grid overload at bay.