Solar gives power in the wrong time, making the duck curve a thing, and requiring conflict prone minerals storing dangerous amount of powers to smooth out. On net, this is probably worth it, but solar isn't free as you claim.
Sodium batteries are available these days. No rare minerals, non-flammable, almost fully recyclable.
One of my favorites is pumped storage hydro.
There's no such thing as a free lunch.
Sure, solar isn't free, but most of the problems it faces aren't exactly insurmountable. In fact, we are already seeing those solutions being deployed in the world - mostly for economic reasons.