Tesla's $12.8 Billion Secret

Ask most people what Tesla does and you’ll get the same answer: they make electric cars.

Some might mention the Cybertruck. A few will bring up Elon Musk’s latest tweet. The really informed ones will talk about robotaxis or Optimus robots.

But almost nobody talks about energy storage. And that’s a mistake.

Because while the world debates whether Tesla can sell enough Model Ys to justify its valuation, something remarkable has been happening in the background. Tesla’s ene...