First, I do not know, it has been caused by an Inverter or a Panel,

but, I am suspecting that the problem is happening by The Inverter.


Because I have verified with MPPT charger with same panel, and similar condition,

and, the power generating is +1/3 and shade two cells, and +2/3 when shade one cell.


Everybody know the shadow can reduce the power from Solar Panel,

there are 3~4 strings in a panel, if shading a string, the other strings can operated normally.

What will happen there is very small shadow 1-2 cells in a 60 cells panel ?

Yes, it can reduce the production to 30~60%,


Look at the detail production yield at my house,

Sunlight is coming from Right-Top side and, Dommer at Right Hand Side is making a shadow on Panel #6,


#1, at 09:19AM, half of two cells (right-top side, two cells in horisontal, not a panel) are shade, power production is just 10% via the other panel.

#2, at 10:23AM, very thin shade on a cell of panel (around 10~20% on right-top side of cell, not panel), production is 80% via the other panel.

#3, at 10:29AM, no shades, same power gain via the other panel.


In the solar panel test with MPPT charger,  the minimum power is aroudn 60% in #1, 90% in #2

It makes me suspect There is a critical problem in Enphase IQ inverter.


Note. Enphase IQ 7+, LG350N1C-V5










Finally, I have got PTO, and my solar system start to work ~




Test Site


I have started to use SQL server for logging data,

Actually, home_monitor software will collect the information from Envoy & Battery remotely,

and upload the data on website by calling solar_data.php


I am using jpgraph ( for the line graphs,

and just GD line drawing for home layout.               configruation related database

solar_db_initial.php      initialize the database, and add the initial data records

solar_data.php          add some data into db, and get solar informations


chart_panel0_inc.php    house layout drawing information has hard-coded, and location of panel will be

                      referenced from dataset in DB,