Hi. I bought 2 panels rated as 300w@30v. On a full sunny day, midday, my victron controller measured 254 w @ 19v, 13.1 amps? I then measured one panel only, I got, 154w@19v, 7.4 amps! Full sunny day! I believe these panels are falsely advertised? Can anyone assist me to ascertain whether these panels are faulty,? Or have I been scammed??
Thanks already.
The solar output will vary depending on temperature and actual solar radiation. Depending on where you are located there are a few websites that show what output you could expect from your panels.
Are your panels tilted towards the sun?
Unfortunately there are a lot of people selling cheap panels with unbelievable ratings. I generally work on cheap panels being 15-20% efficient. That means to be capable of 300w they need to be 1.5-2.0 square meters in size. If your panels are smaller than that it is highly unlikely for them to output 300w.
A lot of 300w panels on eBay are only around 1000x670mm so tend to only be about 140w actual output.
Can you tell us the brand, model and size of your panels and your rough location, then we might be able to help more.
Hey Vance, thanks for you reply,
Panels are 1300x990 mm, when measured the sun was full and at about 80deg, would expect 80% of capacity? Which should be min 480-520w@30v! Max I got was 256w, I believe these panels are falsely advertised!
The brand is rich solar, I am in SEqld,
I measured my old panels, 4x120w@12v in series, and got 430w output, 2 weeks ago! Midday,
Which is about correct?
As soon as I am positive about expected output of 2 300wx30v panels, I intend to go to consumer affairs. Because my victron 30 amp controller is very accurate.!
If I could I would post pics of output.
Your help is appreciated.
Regards
For Australia, I like This website as a guide to expected output.
My panels (second hand Trina laying flat) tend to do slightly better than it indicates, but it gives an idea of what other systems achieved and can be narrowed down to different parts of Australia.
Hey Vance, I looked at that WSite, and I know my old panels Achieved 90% off output midday, not 60% as stated. These new panels don’t even get 50% of advertised output? At the same time? I believe they are not 300w panels! But 150w panels advertised as 300 w panels?
I think that website works off panels which haven’t been cleaned in two years. But it gives a baseline of daily solar radiation. I would possibly say any new panels not achieving what they say are either faulty or falsely labeled.
Those dimensions would indicate 190-240w panels. It seems like one panel has an issue like Michel suggested.
I would definitely say they are falsely labeled however.
I got caught on some ‘250w’ panels that I originally put on my motorhome, that’s why I work off the dimensions now. There’s a lot of scammers out there.
Thanks Vance, I panel had a small dent in the corner? However it is still outputting 105 w, the other one is outputting 146w? Same sun, same time! These are not 300w panels! Off to consumer affairs. We go, hi ho hi ho.
Hi ! Will suggest that you check the weldings inside the box containing the diodes. It can be a problem related to a cold welding, a not welded wire from the panel itself, a diode not correctly welded or even DOA.
It did happen to 2 of my 34 panels !
Michel.
Hey Michael, brand new panels? Money back, or replacement! No panel repairing for this little black duck! Cheers.
Yep, brand new panels ! It can happen during transportation, any other reason, but you will learn about your panels, how they are made, how you can fix them by yourself... Always important to know how things work and interact between them... Just my point of view.
Have a nice day.
