Lithium allows solar already to replace fuel. Does it?
Sodium is cheaper so the battery will be cheaper is certainly naive. The prices are not made from the costs of the components but from the market. Sodium batteries will have trouble to compete price wise in the beginning, because the production industry must be build in Europe and compete against an established industry in Asia. On the long run, you may be right. But for introduction, I have strong doubts. Needs a good marketing, as they have the same capacity, but are heavier.
