I have 6x550W Jinko tiger pro 72H, located in Lebanon @34.5 degrees Installation is West facing on a sloped roof about 15 degrees. Current peak output is 1550 to 1580watts average was for the mid Dec till today. Is this acceptable to be at 50% of theoretical rating?

No. Not acceptable IMHO. But... you are West facing so you lose out from 06h00 to about 10h00, maybe 11h00.

How are you measuring delivered output?

Single MPPT or double? Your inverter may require higher DC voltage. You may need to add more panels to get to 380V or so to unlock the output.

This is at the depth of your winter, west-facing, and also at a low angle which is more suited for summertime generation. Try to find a suitable online solar calculator to work out your likely generation for your location, but you might just be unlucky and have a poor panel orientation. I am at roughly the same latitude South, panels pointing almost North with a better 45 degree slope, and usually I get a Wintertime peak of around 75%.

Just to add to this - I used this link to the PV-Watts website, entered your slope of 15 degrees, 3.3kW of panels, the Azimuth of 270 degrees, and I used Beirut as the city. Closest data it had was for Damascus Syria, but I suppose this is fairly similar, around 100km away. And the actual data is rather low - if you check the attached csv file with the hourly output and check near the bottom of the table in the 12th month at around midday, 12:00 and 13:00, it indicates that your 1580W is actually very reasonable, a good output for the approximate location, and time of year. You have effectively around 2.6 sunlight hours in Dec which is very low.

On the bright side, your power output in June goes up to around nearly 2700W, much better and closer to nominal, but you are still hurt by the fact that your panels face West.

pvwatts_hourly.csv

https://pvwatts.nrel.gov/pvwatts.php

 

Thanks guys this "doubt" with this setup was related to some issues I had with this inverter model's output voltage regulation which was rectified and corrected by a simple firmware update. I just wanted some reassurance that this is within norms of expectations or maybe a subpar panel or another firmware glitch restricting mppt output. 

Another confounding factor is that i have a similar 6 panel setup at my summer home, but I had a flat concrete roof and no constraints in angle/orientation, so i installed it due south at 35degree tilt, it's been impeccable in output peaking at near 3kw in the summer and clocked 2.4kw today at 10am then fog hit. So comparatively getting max 1.5kw at peak hours and clear days in this setup got me worried. Add to that that the other setup starts producing 200-300w at daybreak with voltages in the 220-230s ...starting 7am. Here by 9:30-10 i am still getting a miserable 10 to 30 watts with barely hovering around 120v. 

PS:

- I am monitoring both on my phone app both sites and via a direct serial connection via watchpower. 

- Single mppt on both setups. 

Edited January 4, 20232 yr by mafiose13

location 1 : 9AM West facing, 10 Degrees....mediocre pv production 1 Watt !!! 

Location 2: 9AM North facing, 35 degrees....already at 1.7kw 

Both @ 6 panels 550W each, same  brand Jinko.