The cost of solar panels is plummeting, and this will flood the power grid with cheap electricity. But that’s just Act 1. We won’t stop building solar at the limits of the grid - we’ll build a lot more.
This post explains why we'll keep building more,
Factories often kinda have to run 24/7 so only firing up the furnaces/other electricity intensive machines when electricity is cheap isn’t feasible in most cases
I’m not saying factories should be forced to switch machinery like with ripple control systems in Soviet countries (contactors in households and industry switching based on signals superimposed on the 50Hz grid), there should just be an appropriate economic incentive in doing so. If it’s not enough to offset equipment cost, the factories can ignore it.