I foresee -ve prices becoming more common. Overproduction is a cheap way of dealing with the variability of a source that is 2-3x cheaper than others even if it ends up not being used or if some is wasted (e.g. wind turbines that are left turned off when it's very windy and grid demand is low).

If that overproduction can be channeled into e.g. hydrogen production which can be used for airline fuel or heating homes or for topping up the grid when it's not windy or sunny all the better.