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…