question

Initial thoughts are that you seem to have 3 sub arrays of solar modules pointing in different directions. These should be connected to 3 individual MPPT's.

Solar modules will only give full output when the sun is full on to the module - changing the angle of incidence reduces the output significantly. From your rough description above, 7.5 hours to replace the 13,000kWh sounds about right.

A lot will depend on your location, and exact orientation of the arrays. You may get more output by placing all the modules in the same plane, and orienting it south (or N if you're south of the equator), with the inclination equal to your latitude. This will certainly be the case if you only have one MPPT.

Hi

Having multiple panels pointing in different directions on one string isn't a good idea. The strings will effectively act as if they are permanently partially shaded. It should be noted panels that are more than 45 degrees off their optimal facing angle will also see a significant reduction in power generation.

There are three ways to address this:

1. Ideally your main array should be north or south facing (Depending on the hemisphere) and on its own string. You could add optional east and west strings. This is similar to what you have now, but each direction is on its own string.
2. If you don't have the luxury of a north/south facing mounting, you can have other orientations but then need to have one to capture the morning sun and one the afternoon sun. Each array needs to be on its own string. You also need to increase the size of the array to compensate for their reduced power generation due to the non-optimal angle.
3. If you cannot restructure your array or obtain more MPPTs with more strings, you could reduce the impact by implementing bypass diodes to ensure the "shaded" panels are bypassed. This will offer some relief.

Hi Mike, I do have 6 arrays, 4 of them pointing south, and 2 pointing west. connected on the same mppt. As long as your panels have Schottky Diodes integrated, they are protected against any loses due to the installation with other panels in parallel.

No need to have 3 mppts, it works really nicely. I did use in the past 2 mppts, which were "synchronizing" during the charge, and it was a major problem when they did enter the absorption phase, as one was mastering the other, and disabling it ! So it was unable to finish properly the absorption stage.

Using 1 mppt will avoid such problem.

PS: I have optimized the angle of my panels for winter time (60 degrees), as in spring, summer and automn I do have enough power even not being optimized for such periods.

Michel