France's own Renault Zoe EV

File this under the "if it's not one thing, it's another" department. France, whose largest automaker Renault is already addressing concerns over what may be less-than-expected demand for electric vehicles, has a power grid that may be insufficient should consumers adopt plug-in vehicles in substantial numbers, Reuters says.

The culprit is a combination of France's extensive use of nuclear power, which lacks the flexibility to cope with power-demand surges, and the widespread use of electric heaters during France's cold spells, which already strains the country's power supply. With France shooting to have 2 million plug-ins on its roads by the end of the decade, the prospect of more power-demand surges may further highlight France's power-grid limits, Reuters says, citing executives with some of the country's utilities. Fast chargers use about as much energy as a dozen electric hot-water heaters.

France's utility executives and analysts are hoping technology advances such as smart-charging, which facilitates off-peak grid use, may mitigate some of France's power-supply issues.

Renault started sales of its all-electric Zoe this month. Last month, the French government said it would order about 2,000 Zoe vehicles and 100 Fluence Z.E. EVs over the next three years.