Parallel strings and overpaneling or how to maximize PV production on a single inverter.
In the past I was told that you could safely add 20% more panels to an inverter than the name plate rating, i.e. on a 5kw inverter, you could put 6,000 watts of PV panels. New SMA docs say you can overpanel by 60%. i.e. you can add 8,000 watts of panels to a 5,000 watt inverter. On new SMA inverters that are coming out you can supposedly overpanel by 100% i.e. 10,000 watts of panels on a 5,000 watt inverter. From what I understand the extra power is just not used (whatever that means).The most it will ever put out is 5,000 watts.
Back in the day when panels were expensive, overpaneling was not practical, but now with prices so low, overpaneling and stings of different orientations are practical.
A 5,000 watt inverter is only producing max power of a few hrs. at local noon (assuming relatively sunny (shade free) location.
The question are: How can you maximize output on 1 inverter? Can you get it to produce 5,000 watts continuously from sunrise to sunset? What do you have to keep in mind?
In general, panels are oriented due south for maximum output. That leaves the mornings and afternoons with low power outputs.
Say you already have 6,000 w of panels facing South on 2 MPPT inputs. Say you want to add 2 more arrays, both vertical to capture early morning and late afternoon sun, but 1 facing due West and the other array facing due East. That is ok as long as the min max DC voltage and amperage conditions are met?
Can you put both arrays on the same 1 string? You only have to meet the min dc voltage? They will never both produce power. Or should you put 1 array on each input? i.e. South plus East and South plus West? Can you put 3,000 watts of vertical East facing panels to the same input as the 3,000W of South facing panels?
Can strings be different sizes, i.e. 1 string of 8 panels facing West and the other 10 panels facing East? Both connected to same MPPT input as long as the min DC voltage is met?
Can you mix strings of different voltages? If yes how? Can you have a string of 3 panels at 100V be connected to a 300V string facing a different orientation?
Are microinverters maybe a good solution for some of these situations? The ones on Amazon seem to overheat and shut off, plus they seem to fail rather soon.
If there is a sunny area, but it only fits 4 panels, can those 4 panels be connected in parallel to a different string. Keeping in mind not to exceed the max current.
Lets say you have an area that gets 2 hrs of good sun, how can/should you connect that to the inverter to capture those 2 hrs of power?
Example:
Sunny Boy 5.0-US Inverter
3MPPT trackers, 1 string/MPPT tracker
Max DC Voltage 600V
Max PV Power 8,000Wp
Rated MPP voltage 220V-480V
MPPT operating Voltage 100-500V
Min DC start Voltage 100V/125V
Max operating input current per MPPT 10A
I’m guessing there is a simple rule that you can apply to all of these situations.