@Lianaguoss
It is very simple maths.
You generate X amount of solar.
You get paid for Y amount of solar.
If X is in kW and Y is in kW the answer is X-Y.
If X = 40 and Y=13 the resultant is X-Y or 27.
Therefore you consumed 27 kW and got paid for 13kW
This is called applied mathematics
Now your X is your investment in cheaper electricity, the Y is your perceived return.
You need to realise that you did not invest in solar to make a profit but to reduce the cost of your power.
We spent $3300 on our solar and it took some 18 months to return our investment. We got free hot-water, did not pay for any electricity and got a return.
Again do your basic maths.
Cheers Neil
If this comment solves your issue please solve the post, if you like this comment please take the opportunity to click the Like button below.