Choosing between a bigger array and a battery
The bigger-array-versus-battery question comes up in almost every quote, and the honest answer is that it depends entirely on when you use power. If your consumption is daytime-heavy, more panels almost always beat a battery. If it is evening-heavy, a battery usually wins.
The line is around 40 percent self-consumption. Households above that threshold get more value per dollar from additional panels, because they use the extra output directly. Below it, the surplus heads into a low feed-in tariff and a battery that shifts it into the evening pays back faster.
We model both options against your actual half-hourly usage and show the payback for each side by side. Often the right answer is a modest array plus a battery, rather than maxing out either one.
