Is this how much i am really supposed to get from a 5kw system?

kyledsh

So i have a 5kw grid tie system located in Quezon City, Philippines, the panels are facing west and tilted following the slope of the roof. but i dont know if i did some installation wrong that is causing me to only get this production. i just installed it the whole system myself last Feb 8,2017. Is this production just typical?
Lowest Production:
Feb 17,2017 - 6.5kwh
Feb 18,2017 - 6.8kwh
Previous Days Production:
Mar 6,2017 - 19.7kwh
Mar 7,2017 - 18.8kwh
Mar 8,2017 - 11.3kwh
Mar 9,2017 - 16.5kwh
Highest Production so far:
Feb 15,2017 - 20.9kwh
Typical Production:
10-15kwh/day
Solar System:
Solar Panels: 20-260w trina solar panels - http://static.trinasolar.com/sites/default/files/PS-M-0323%20E%20Datasheet_Allmax_US_Feb_2017_A.pdf
Inverter: Growatt 5000UE - http://www.growatt.com/html/2014/01/10/2014011010480983423919.html
I used 4mm2 pv cable that run a length of approx 25m.

Should i also use a thicker pv cable? and is the Current from the panels a little high for the inverter?

bill von novak

kyledsh said:

So i have a 5kw grid tie system located in Quezon City, Philippines, the panels are facing west and tilted following the slope of the roof. but i dont know if i did some installation wrong that is causing me to only get this production.

You are getting 3.5-4kW peak out of a 5kW system, which is reasonable.  Beyond that I see a lot of clouds and lensing effects in the plot, so the weather wasn't great.

mcgivor

Without going into any details electrically, the fact your panels are facing west would be a factor of low production, you are at 14.6 degrees north, so a south facing array would be optimum. Depending on the angle of the roof, your panels are probably shaded, for the first couple of hours, reaching a peak at around 11:30, afternoon harvest looks to be good. The panels being on a roof would probably be getting hot and reducing output not having air circulation, panel output would be lower than rated under normal conditions in 30C+ temperatures, perhaps around 75%, weather is another consideration, cloudy or partly cloudy will reduce production.

My 1.5KW array can produce 5+ Kw on a good day, off grid, so not optimal for maximum output reading, my latitude is 17.6 degrees north, ground array, facing south, temperature 30C+, angled 30 degrees from horizontal, very similar climate, different orientation.

kyledsh

I used 4mm2 pv cable that run a length of approx 25m. DCV:330V DCA:9amps. Should i use a thicker pv cable?

mcgivor

kyledsh said:

I used 4mm2 pv cable that run a length of approx 25m. DCV:330V DCA:9amps. Should i use a thicker pv cable?

4 mm is equivalent to 12 AWG, which is rated for 20A, so your cable is probably fine as long as the runs are within reason.

Photowhit

The max power output is about right, Normal Operating Cell Temperature (NOCT) values will be about 75% less than the name plate. In this case Trina publishes the expected output values in the 2nd graph, they expect the 260 watt panels to produce 193 watts in normal heat or (193/260=) 74% of the panel rating and you are close to the equator so you're going to be hotter than most areas.

Between that and the west facing array, it looks like reasonable numbers.

BB.

Using PV Watts for your location. 18 degree roof pitch (guess), facing west, fixed array:
http://pvwatts.nrel.gov/pvwatts.php

Month	Solar Radiation ( kWh / m2 / day )
January	3.37
February	4.04
March	5.05
April	5.35
May	5.12
June	4.42
July	4.23
August	4.26
September	3.75
October	3.64
November	3.44
December	3.02
Annual	4.14

For March, your long term average power would be estimated to be:

• 5,200 Watt array * 0.77 typical GT system eff * 5.05 average hours of sun per day = 20,220 WH per day = 20.2 kWH per day average

Either you have bad weather, shading of panels (ANY SHADING of even 1 panel can cut your production upwards of 30-50%--Even just shadow from power lines across your roof), or possibly bad electrical connections or solar panel(s). If you are having clear days and closer to 10 kWH per day--It does not look right.

Can you borrow a DC Current Clamp meter? Measure the current from each array. The numbers should be very close (withing 5%-10% worse case). What is the Vmp-array and Imp-array numbers that your GT inverter are telling you in the middle of the day (high noon or so).

Any clouds over your area can reduce output by 50% pretty easily... Those valleys in your power production charts--Are those clouds or other shading events? Or was it clear and sunny all day? (unexplained valleys could be loose wiring connections--check screw terminals, poor crimps on connections, or a bad GT inverter).

-Bill