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…
Seems like using that extra juice to run the water heater is a good use of it. I’d have all sorts of electronic gadgets running all the time, like pumps in a water feature, mood lighting, landscape lighting, etc. Get electric everything (tools, lawnmower, car, etc ), and keep it all charged, all the time.