> the amount of batteries required is significantly more than current lithium battery production worldwide.

Indeed, hence why Tesla is building and consuming as many cells as possible. They are bootstrapping utility scale storage supply chains as part of their EV endeavors, and every cell they produce is sold. With that said, overbuilt renewables, renewable curtailment, and robust transmission infra (HVDC, interconnects, etc) will all be components of a clean energy grid.

https://www.weforum.org/agenda/2018/03/100-tesla-gigafactori... ("100 Tesla Gigafactories could power the entire world with sustainable energy")

https://www.utilitydive.com/news/tremendous-demand-for-stati... ("'Tremendous demand for stationary storage' outstrips Tesla's 2020 supply capability, Musk says")