Forum Discussion
Lwiddis wrote:
Red, they all rated 100 watts. Poly is supposed to be more efficient. Mono needs three more cells to “make” 100 watts. Test didn’t show more efficiency.
But it does show more output in watts from poly vs mono unnder all the tested conditions.Lwiddis wrote:
Red, they all rated 100 watts. Poly is supposed to be more efficient. Mono needs three more cells to “make” 100 watts. Test didn’t show more efficiency.
then why were the poly 36 cell and mono 33 cell???
the fles was 32 cell!
As a pwm user in hot weather, the Vmp is important.- They went to 36 cells to get the voltage into the 14s to charge batteries properly, where the 33 cell ones could not. They still have an issue with 60 cell panels vs 72s when doing 24v.
jimindenver was the member who showed poly was better in low light and shoulder hours ISTR. - I went with what the dealer sold me and didn't know any different! Turned out to be Samlex Poly's for 150w @ $500.00 each. They work fine, but surely I could have done my self better for the $1650.00 I have invested in the 3 panels and the wimpy 30a PWM charger. I knew no better at the time, but I know better now, and it'd be best if others learned from my errors.
- 30a is ok for 450w mounted flat. Not wimpy at all. Leaves a little room for cold ambient. It would not leave proper margin for cold ambient with aimed 450w at high noon where it would be close to 30a. The controller will warm up too much if you go over its 30a rating for very long. Cloud effect short times are ok.
Vintage465 wrote:
surely I could have done my self better for the $1650.00 I have invested in the 3 panels and the wimpy 30a PWM charger.
there is an old saying about get what ya pay for that comes to mind! :B- red31,
What Vintage465 is saying is that he was ripped off. Panels are often priced below $1 per watt and that has been so for many years now. pianotuna wrote:
3 tons wrote:
“ The mono is better for RV use. Mono should be more efficient. In reality there is minimal difference, but I spring a few bucks extra always for the mono.”
Agreed, but this additional efficiency manifest itself via a smaller footprint - regardless of which substrate, 100w is still 100w, thus I find the panel presenter’s conclusions a bit lacking...
That is the exact opposite of what the testing shows. Poly works better except when solar conditions are perfect. Since he did not test in ideal conditions, we have no way of knowing if mono would truly outperform poly.
The first "hints" of this were published on rvnet a lot of years ago when someone by chance bought two panels, one poly and one mono. The poly out performed in real life conditions. And yes the poly are always larger.
No matter how one cuts it, 100w is still 100w - this, the 800# Gorilla in the room...These 100w have no idea whatsoever whether they are coming from poly or mono because watts = power, thus his demonstration rings hollow...3 tons wrote:
What he doesn’t attempt to make clear is, why do two different types of panels (differing in substrates and size) that are rated at the same wattage (i.e. Power) might produce results that are different than their manufacturer’s 100w ratings??
3 tons
The 100 watt rating of the panels is "Ideal conditions"
The roughly half that he observed is "Real Conditions".
This is well known.- 3 tons,
The 2 mono and 2 poly were all rated at 100 watts. The poly's out performed the mono's in all the tests. How does that make the results "ring hollow"?????
