Tesla's claim that they will producing batteries in a net-zero factory is almost certainly not true. They could do it by using their batteries and solar panels,

Tesla's claim that they will producing batteries in a net-zero factory is almost certainly not true. They could do it by using their batteries and solar panels, but they almost certainly won't do that because they want reliability and affordability (like the rest of us). They will buy credit and that's where there claims of "net zero" come from. But they will almost certainly use grid electricity.