Every kilowatt-hour your Perth solar system generates either replaces grid electricity you would have bought (at 33.26c/kWh) or exports to the grid under the DEBS scheme (2c/kWh off-peak, 10c/kWh during the 3pm-9pm peak window). Since most solar exports happen during the 2c off-peak window, self-consumption is usually worth 31.26c/kWh more, and still worth 23.26c/kWh more for the smaller share of exports that land in the 10c peak window. Either way, self-consumption is almost always the better outcome, but the practical question is how much you can actually shift.
