Elon Musk is among the most controversial titans of Silicon Valley. To some he's a genius and a visionary and to others he's a mercurial huckster. Billions of dollars have been gained and lost on his tweets and his personal exploits are the stuff of tabloids. But for all his outrageous talk of mind-uploading and space travel, his most audacious vision is the one closest to the ground: the electric car.

When Tesla was founded in the 2000s, electric cars were novelties, trotted out and thrown on the scrap heap by carmakers for more than a century. But where most onlookers saw only failure, a small band of Silicon Valley engineers and entrepreneurs saw potential and they pitted themselves against the biggest, fiercest business rivals in the world, setting out to make a car that was quicker, sexier, smoother, cleaner than the competition.