Last year, roughly 118,500 plug-in electric cars were sold in the U.S.--out of total vehicle sales of 16.5 million, the highest total since 2006.

Since modern electric cars went on sale in December 2010, sales have increased every year.

Any increase this year may not be as dramatic as in prior years, largely due to model cadence issues.

DON'T MISS: Will 2015 Plug-In Electric Car Sales Exceed Last Year's Total?

But how long will it take for sales of cars with plugs to reach the magic 1-million-a-year number in the U.S.?

According to a new report from Navigant Research, sales likely won't cross that level until 2024.

The report, entitled Electric Vehicle Geographic Forecasts (via ChargedEVs), predicts that North America will continue to be the world's largest single market for cars with plugs.

2015 BMW i3 REx - Driven, Portland OR, April 2015

2015 BMW i3 REx - Driven, Portland OR, April 2015

(It also gives a slightly higher total for 2014 sales, of roughly 133,000, most likely including low-speed neighborhood electric vehicles as well.)

Navigant's report proposes different scenarios: It suggests that yearly plug-in sales will run about 860,000 under its “conservative” scenario, and come in at more than 1.2 million in the “aggressive” scenario.

As always, California will be the area with the highest electric-car penetration.

ALSO SEE: Plug-In Electric Car Sales Continue Rise In 2014, To 118,500

Navigant predicts that 15 percent to 22 percent of all new cars sold in the state will be either battery-electric or plug-in hybrid models by 2024.

Market penetration in California for plug-in cars is already 3 percent, against less than 1 percent nationally, and that difference will continue, it suggests.

The 10 other states that have adopted California's requirements for zero-emission vehicle sales should also have greater sales penetration than the national average.

2015 Kia Soul EV and 2014 Nissan Leaf, at Blink DC fast charger - Fife, WA

2015 Kia Soul EV and 2014 Nissan Leaf, at Blink DC fast charger - Fife, WA

Finally, the report notes the imminent arrival of a new generation of battery-electric cars with ranges of 150 to 200 miles, at prices under $40,000.

Those models include an updated Nissan Leaf, the 2017 Chevrolet Bolt EV, and the promised Tesla Model 3--among others.

They are likely to find wider acceptance among a larger number of buyers, Navigant suggests, than current offerings with rated ranges of 62 to 104 miles.


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