> Electricity is priced at the edge entirely because demand must match supply at all times. You either meet all electric demand or someone will go without power.

There's also more to it than just that. Supply-demand imbalance affects the frequency on the grid. Too high or too low frequency damages the turbines in the base load power plants, and they will shut down to avoid damage if the frequency goes too far out of range. Hence, too little or too much power actually causes grid collapse.

Solar actually has to be managed a lot more carefully than people realise.