Just recently noticed that at times my 3 PV200 panels connected in series sometimes appear to be giving me up to 10% more power than the technical sheets says.
Here is a pic from today, where I am over by just 2%.
I wonder if this is a calibration problem with the BMS or SOC indicator.
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Hi @Liberty
there is one really simple answer to this.
Solarpanels are tested in a labor at 25 celsius degrees. If you have a sunny day and well under 25 degrees, The Solarpanels can actually output more than measured in the labor. The efficiency rises when its colder outside.
Just a lucky moment, where everything fits well!
greetings
Erik
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Thanks all. Now I know.
Yes the days that I have noticed better than expected power levels the temperature was well below 25c. Around here at this time of year the average daytime highs are around 5-8c.
Also some panels give you a view percentages extra.
And the PV200 is not exactly a precises measuring instrument
Solar panel ratings are not exact. Kind of like computer chips. They make them to an estimated spec and then they test it and group them into “bins” with range of power output. So you sometimes see a series of solar panels that are rated at 300W 310W 320W 330W 340W, they may actually be made at the same factor line, just some are tested to perform at a specific level and thus is given that label and sold as such. This way, a 310W panel is actually tested to be 310-319W, if it is 320W then it would be labeled and sold as at 320W panel at a higher price.
.
Liberty is right that panels are tested at a certain temperature and condition. If it is a very bright day and cold, you can certainty get more than the rated power. Unless it is really cold and there is a breeze, that condition doesn’t last as the sun heats up the panel and then it warms up and produces less power. In fact, you should consider yourself going very well if you get 90% of the rated power from the panels. 80% is more typical.
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