What is the difference between these panels??

[Perdiem]

Hello. If there is a thread somewhere that answers this, could someone kindly point me to it? I am looking to install 3 - 100 watt panels but I need them to be "compact size" - roughly 20" by 40" (500 x 100mm). Renogy has three that would fit and they are $105, $150 & $210 Canadian each. The specs all look the same to me so after waiting on the hold with Renogy for 40 minutes I emailed them and got this wholly unsatisfactory response:

In regards to the difference for the 3 panels that you have listed, yes they are all100w panels but the main difference is in regards to the dimensions, number of cells, and some specific details regarding efficiency when charging.

Should you have any other questions, please call us.

So I called them and the gentleman who came on couldn't name one spec that was different between the three panels except for the number of cells, where the cheaper one had 33 and the other two had 32. He couldn't say why one was better than the other. The optimum voltage, optimum current and open circuit voltage were all within a volt or amp of each other and the dimensions were all within an inch of each other.

The only thing he said was the more expensive ones were better in low light conditions and the most expensive one was part of their new "Eclipse" line which is apparently more efficient.

I guess I'm more used to buying a TV where if one is twice the cost for the same size the salesman can point to a dozen different specs that (rightly or wrongly) justify the extra cost.

Here is a link to each one along with the detailed spec sheet for each one. What I would like to find is a certain spec that I can use to compare panel efficiency or quality across brands.

Or maybe I should just ask the collective wisdom here which one is best and go with that!!

$105 CDN:
https://ca.renogy.com/renogy-100-wat...RoCZAcQAvD_BwE

https://www.renogy.com/content/RNG-1...-Datasheet.pdf

$150 CDN:
https://ca.renogy.com/renogy-100-wat...l-black-frame/

https://www.renogy.com/content/Speci...-BK%20spec.pdf

$210 CDN:
https://ca.renogy.com/renogy-eclipse...e-solar-panel/

https://www.renogy.com/content/files...0MB%20spec.pdf

Many thanks,
Gregg

[George_SD]

There are small differences - different size of cable used, some style/color difference, minor electrical spec differences, but nothing to justify the price difference in my view. I would go with $105 ones.

[japawil]

The $105 model is on sale - normally $140. So usually only $10 difference between it and the $150 model, which is also 2lbs lighter (possibly something to consider).
If all fit your mounting area size wise and the 2lbs weight differential isn’t a prime consideration, I would go for the model on sale and put the savings toward the wiring, mounting and controller costs, which in my installation cost more than the panels themselves. I got 2 of the lighter model when they were on sale and therefore the most cost efficient option at the time.
I personally couldn’t justify doubling the cost for the difference of 22% and 21% efficiency.

[Perdiem]

Thank you both! So basically I'm further ahead just going for the most watts / dollar and ignoring the marketing noise?

Gregg

[George_SD]

That is my read based on the information i see in PDFs. There may be significant differences, but I haven't seen them. If manufacturer can't point to them, then yes - probably marketing.

[japawil]

Originally Posted by George_SD

That is my read based on the information i see in PDFs. There may be significant differences, but I haven't seen them. If manufacturer can't point to them, then yes - probably marketing.

[emoji106]

[waterman46]

Originally Posted by Perdiem

Thank you both! So basically I'm further ahead just going for the most watts / dollar and ignoring the marketing noise?

Gregg

Your best defense is to get reviews from users of the product and base your decision on that.

[noelex 77]

The panels do differ slightly in efficiency.

The $105 100w panel is 827.1 sq ins
The $150 100w panel is 861.1 sq ins.
The $210 100w panel is 858.9 sq ins

Higher efficiency panels with a smaller size for a given output are often significantly more expensive. Whether or not this extra cost is justified depends on your application. On a boat the available space is often limited, especially the available area that receives minimal shade so in many cases paying considerably more for higher efficiency panels does make sense, but it also depends on how the dimensions of the panel fit in the space that is available.

In the case of these panels, the difference is only small. All the options are medium (rather than high) efficiency panels. The best one of the three has a panel efficiency of 18.7%, but the strange thing is the cheapest is also the most efficient. It is smaller (less surface area) than the most expensive panel for the same output and is half the price!

Solar panel pricing does fluctuate significantly and these type of anomalies do show up.

It would be nice to see some more information such as the temperature coefficients and low light performance, but on the information Renogy supply the $105 panel is by far the best buy providing its slightly longer but narrower shape fits your installation.

[KP44]

All three choices are monocrystalline panels, which are more efficient for their size.
That is the only spec I really insist on having.
If cost were not a concern, you would not be asking here. I would choose the lower cost panel.