Unfortunately what's shipping today seems it would offer maybe half that.

For the batteries that were announced this past week, a larger-than-refrigerator-sized cabinet held a capacity of around 15kWh.

Around half the energy density by mass of Lithium batteries, and in the order of a sixth of the density by volume.

Now if only we could come up with a system where your car could be charged while stopped at traffic lights, we might be onto a winner (:

Considering however that the price of sodium is around 1-2% that of lithium, I expect we will see significant R&D and those numbers quickly start to improve.