What happens if the sun shines onto your solar panels, and you have too much power. I guess you could cover the panels with a blanket in such a case, but that would be manual intervention …
Do you need to consume all electric power you generate? Ways of wasting power include … heating water or electrostatics.
Most people would put surplus power they produce into the grid, but this is connected to government / cooperate regulations and paperwork, some would like to avoid that.
An island solution with solar panels is not connected to the power grid at all…
I’ve asked the same question before for small scale at home surplus.
For a small/medium grid like a whole island, it’s easier. You generally know ahead of time when there is going to end up being a surplus, so you can let storage get low preemptively. This includes batteries, pumped hydro, heating water, heating/cooling homes, etc.
If that’s not enough, you can run some high energy cost things that dont have to run all the time like desalination or electrolysis.