I developed a simulation that used a single inverter with a single MPPT tracker input. I had four strings of seven panels, all in the same subarray (so all on the same MPPT). I used the 3D shade calculator to simulate shading effects.
The results of this simulation produced 9968 kwH in year 1.
I expected that if I added more MPPT trackers and split them up among the strings, it should improve energy production. However, when I do that, the simulation actually has WORSE performance. This seems counter intuitive. I've tried it with one, two, three, and four MPPT trackers. Each time I add an MPPT tracker, the energy production goes DOWN.
What am I doing wrong?
One thing that I did notice is that the losses graph shows that the "AC Inverter Power Consumption" goes up each time I add an inverter. Does it really take that much extra power to run an MPPT tracker?
I also noticed that the shading loss goes UP when adding MPPT trackers.
Not sure if it matters, but the inverter that I'm using for simulations is the <>. I haven't necessarily decided that this is the right inverter - I'm just using something for now to get rough numbers so that I can decide how many MPPT trackers I need in my inverter.
MPPT | Annual Prod (KwH) | AC Inverter Power Consumption Loss (%) | Shading Loss (%)
1 | 9828 | 0.67 | 7.461
2 | 9794 | 2.64 | 8.052
3 | 9587 | 4.26 | 8.608
4 | 9415 | 5.88 | 8.81
