You are not allowing for a 10% increase per year in Elec pricing which effectively works to an extra 10% saving per year
You would then be looking
Just when you thought, great my system is optimised and my system is saving me R 791.59, this is not an average, it is the best month of the year, then
Tradie Today, 08:37 AMBill from the utility - import 707 kwh
707 kwh x R2.97 = R2099.79
The saving would be the PV used plus the PV exported
Lets look at the numbers from the inverter, some figures randomly taken from an inverter
PV - 325.7
Load - 885.7
How much money have you actually saved installing solar ?
On any solar system if it is an over design on PV and especially batteries the pay back period will become longer.
GCE Today, 12:05 PMIt would be like starting