That project was 200 MWh. 1 day of Germany electricity consumption is on the order of 1,400,000 MWh, something like 7,000x larger. A "few days" of electricity

That project was 200 MWh. 1 day of Germany electricity consumption is on the order of 1,400,000 MWh, something like 7,000x larger. A "few days" of electricity storage would take orders of magnitude longer to build and deploy, even if we worked on Elon's most optimistic timeline.