Can any one tell me why there are so many almost identical panels being offered by the same company? I'm looking at JA at the moment, but I know that Canadian Solar at least do the same thing. JA have list a 365w & 370w, a 380w & 385w, a 455w & 460w, and a 540w & 545w. This feels like an incredible small difference in spec to warrant a whole different part number etc. I haven't pulled the full specs and looked a power delivery curves and stuff, and I wondered if anyone else has, and what you found. They're all the same at a basic spec level, ie mono, perc, 144 half-cell etc.

Jay

On 2022/12/13 at 2:11 AM, farmer barnes said:

Can any one tell me why there are so many almost identical panels being offered by the same company? I'm looking at JA at the moment, but I know that Canadian Solar at least do the same thing. JA have list a 365w & 370w, a 380w & 385w, a 455w & 460w, and a 540w & 545w. This feels like an incredible small difference in spec to warrant a whole different part number etc. I haven't pulled the full specs and looked a power delivery curves and stuff, and I wondered if anyone else has, and what you found. They're all the same at a basic spec level, ie mono, perc, 144 half-cell etc.

Jay

I would say we all have different needs and great to have the selection. One might want to go normal max plus 10% then to not exceed 10% one might work a specific size.

5w in 540w is less than 1%. I can't believe anyone is tuning their system that finely - a bird flying across the panels could cause a 1% difference. And they're the same physical size as well. 10% difference I could understand, eg 540w --> 600w, but as it stands I don't get it.

12 minutes ago, farmer barnes said:

5w in 540w is less than 1%. I can't believe anyone is tuning their system that finely - a bird flying across the panels could cause a 1% difference. And they're the same physical size as well. 10% difference I could understand, eg 540w --> 600w, but as it stands I don't get it.

Its all about yields... the manufacturer of panels aims, for say 390W and done and dusted and tested under some standard conditions, some panels will be 390W and sold as such, those measuring between 385 and 390W are sold as 385W panels etc. so they are not making panels of such close wattage specs, but due to minor imperfections etc. once things are measured you get a spread of power ratings... since you can hardly sell a panel measuring 381W as a 390W panel, it is classified as 380W and sold as such... hope its all clear as mud now...

I wondered about that too. I know resistors work like that - if the manufactured resistance of a 1k resistor is 990-1010 ohms they market it as a 1% tolerance, if it's 950-1050 it's a 5% etc. You think you're getting a better quality resistor, but you're not, it just came out closer to its nominal value than others.

So yes, it's a thought.