You require inertia in the grid to maintain frequency and other stability stuff.
Solar PV is great but is mostly grid-following so cannot operate on it's own. As I understand it you need a minimum fraction of power generation to be large spinning turbines.
I think this problem can be mitigated with add-on rotational mass style kinetic energy batteries or something like that. I don't think variable energy pricing will help if it's an issue with over-demand the grid managers can do rolling blackouts to manage while fixing the supply problems. The grid is just broken at the moment and the solar can't maintain the grid alone.