Panels no giving full power 2700 watts

justnoel

I have 12 335watt JA panels which Taking into account solar radiation in jhb and working at 17 % efficiency should give about 2700 watts bit according to my inverter loaded to 2000 watts it is only giving me 1350 watts

BB.

Guessing that JHB is Johannesburg, South Africa...

Without knowing anything about your system, I would expect the maximum output on a warm/clear/around solar noon day, that your array would max out around:

12 * 335 Watts = 4,020 Watt array Standard test conditions
4,020 Watt array * 0.77 panel and charge controller derating = 3,085 Watts (a few times a year) "best case" output

And, on a "typical day", a little haze in the air, possibly some dust on the array, not quite pointing at sun, it would not be unusual to see 1/2 that or around 1,500 Watts day to day max output.

So, your array is probably under producing, but we need to know a bit more about your system. What are the Vmp/Imp rating of your panels? How are they connected (number of series connected panels, and number of parallel connected strings--Such as 3 panels in series and 4 parallel strings, or 4 panels in series and 3 parallel strings).

Also, assuming this is a battery based system, what is your battery bank voltage (12/24/48 VDC typical) and what is the brand/model of solar charge controller (or "all in one" charger/inverter, etc.)... A link to the system specifications would be handy. Need to know the min/max Vpanel/array input voltage to the system (I.e., 150 VDC Vpanel-max or 600 Vmp-max, etc.).

Also with off grid/battery systems--it depends on the battery state of charge. The array energy may be split between charging the battery bank and running the AC loads--Or the charge controller, may be holding the battery bank at its recommended charging voltage, and simply not using the full array output at that point in time, etc.

-Bill