How a network of ex-Tesla employees created $10 billion worth of U.S. clean-energy investments

From new batteries to EV chargers to battery recycling, ex-Tesla employees are creating a web of new entries into the clean energy space. Here’s what they say working at Tesla taught them.

At a former steel mill in West Virginia, a recently-completed factory is ramping up production of something new: “iron-air” batteries that can cheaply store renewable energy for as long as 100 hours.