Three years ago, Tesla Motors announced its plans to build the Gigafactory, a sprawling lithium-ion battery plant in the parched hills outside Sparks, Nev. Nothing remotely like it had ever been proposed.
The Gigafactory, Tesla CEO Elon Musk proclaimed, would be the world’s biggest building by footprint, spanning 107 American football fields, and it would produce at least 35 gigawatt-hours of batteries per year—more than the entire global output of lithium batteries in 2013.
