Tesla estimates 10 TWh/year of batteries needed for transportation, and another 10TWh of stationary storage, in order to zero out fossil fuels. Tesla itself wants to have 3TWh/year of capacity by 2030, with some split between vehicles and stationary. That's straight from the battery day slides.
(Now, 3TWh in 2030 is an Elon sez goal. And if you've been around a while, you know Elon sez numbers run on the, um, optimistic side.)
Ford's 240GWh to Tesla's 3TWh, that ratio is eerily close to the ratio between Ford and Tesla's market cap! Mr. Market isn't as irrational as everyone keeps insisting!