Yes well when they have installed enough solar panels to exceed the day time demands of the entire country (which is what selling to the grid means) THEN they c

Yes well when they have installed enough solar panels to exceed the day time demands of the entire country (which is what selling to the grid means) THEN they can start worrying about storing excess capacity. N.B. distributed solar currently accounts for ~.25% of electrical generation, Solar City accounting for some fraction of that fraction of a percent.