We're increasingly starting to see one of the "problems" of solar here in California. The duck curve:
https://www.eia.gov/todayinenergy/detail.php?id=56880
It's what happens when solar energy generates the bulk of its power in the middle of the day, but peak energy demand is later in the day when solar energy generation is tailing off.
The duck curve presents two challenges related to increasing solar energy adoption. The first challenge is grid stress. The extreme swing in demand for electricity from conventional power plants from midday to late evenings, when energy demand is still high but solar generation has dropped off, means that conventional power plants (such as natural gas-fired plants) must quickly ramp up electricity production to meet consumer demand. That rapid ramp up makes it more difficult for grid operators to match grid supply (the power they are generating) with grid demand in real time. In addition, if more solar power is produced than the grid can use, operators might have to curtail solar power to prevent overgeneration.
The other challenge is economic. The dynamics of the duck curve can challenge the traditional economics of dispatchable power plants because the factors contributing to the curve reduce the amount of time a conventional power plant operates, which results in reduced energy revenues. If the reduced revenues make the plants uneconomical to maintain, the plants may retire without a dispatchable replacement. Less dispatchable electricity makes it harder for grid managers to balance electricity supply and demand in a system with wide swings in net demand.
I used quotes around "problem" for a reason, because there IS a solution. The solution, of course, is energy storage, but batteries are expensive, environmentally "dirty" in their own right, and the scale of batteries required is massive (other large-scale energy storage ideas are floated, such as gravitational storage, but little to none actually in use), and so storage is not being deployed anywhere NEAR as fast as solar generation.
But it highlights that the technological area where we need to be spending time, if we want to make wind & solar a REAL solution, is in energy storage. Generation is the easy part. Generation when and where it's needed is harder.