According to Wired, by 2022 vehicles that run on electricity will cost less than cars that run on gasoline. What this means, according to Bloomberg, is that electric vehicles will displace oil demand by 2 million barrels a day between 2023 and 2028, creating an oil glut like the one we saw in 2014 (when oil prices collapsed).
If you're asking where the cheap batteries and cheap electricity will come from, you'll be pleasantly surprised by the on-going and accelerating advances made with electric batteries and clean energy, especially in the areas of wind and solar energy. This will turbocharge the shift from petroleum guzzling cars to electric vehicles at a faster rate than previously imagined.
And, as was the case when digital cameras replaced film cameras, the process isn't going to only happen on the cheap-expensive end of the camera spectrum. It's going to happen to all new cars virtually overnight. This, incredibly enough, will be just a prelude to a not so distant future, where selling car units is not as important as selling miles on a transportation unit. Put another way, the cars of the future will be shared rather than owned.
As you can imagine, industry shills from the oil, nuclear and coal markets don't agree. Then again, these industry experts have a financial stake in getting people to doubt what the science and technology are telling the rest of the world. The idea of mass transit, bullet trains, and shared transportation work against the dinosaur industries that dominated the 19th and 20th centuries.
For those of you interested in the economics behind the coming wave of electric cars, and the next oil crash, take the time to read this (from CleanTechnica) and this (from Bloomberg).