Bi-Facial Solar Panels

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wankel7

Active member
What is the issue with them?

Regards,

Mark
Under performing. I honestly think they are 175w panels. They are the smallest 200w panels out there....that should have been my clue. Or 2 for $330 shipped should have been my other clue.

I normally see around 55 to 60 percent of rated. Yes, I know flat mounted late in the year etc.... But even in summer I never got close to 75 to 80 percent of rated.
 
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Boxster1971

2023 Sprinter 2500 144wb AWD
Under performing. I honestly think they are 175w panels. They are the smallest 200w panels out there....that should have been my clue. Or 2 for $330 shipped should have been my other clue.

I normally see around 55 to 60 percent of rated. Yes, I know flat mounted late in the year etc.... But even in summer I never got close to 75 to 80 percent of rated.
Interesting - they are the same size as the quality 170W panels from AM Solar.

https://amsolar.com/rv-panel-klts/11s-tlt-zs170

How are your HighTec panels wired and what controller are you using?
 

marklg

Well-known member
Victron 100/50 and 2S.

It's funny the reason I went with these panels was their size. But I didn't compare them to other 200w panels to notice they were smaller.
That size is somewhat of a standard. I have some very old Kyocera panels that size that are 135W nominal and produce significantly less than that now. 165 W in the same size would be an improvement.

If you look at the spec sheet, the voltage required for maximum power is quite high, about 21V vs about 17.5 V for most other panels. If you don't have a good MPPT controller, you won't get full power, and if they are in parallel with panels with a lower maximum power voltage, they will also underperform. The efficiency loss with a PWM controller is also larger than for most other panels. From my calculations, they would only produce about 125W with a PWM controller charging a battery at 13V.

Regards,

Mark
 

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