Forum Discussion
Bobbo wrote:
I took his output for each panel and divided by the square inches of each panel. The Mono was more efficient per square inch than the Poly, but by less than 5%. The Poly provided more power because they were larger, e.g. had more square inches. My take on this is go with the cheapest (Poly) unless they are just too large to fit your area of application.
Bingo, larger could translate into more capture area (??) - interesting, you may be on to something !!- I took his output for each panel and divided by the square inches of each panel. The Mono was more efficient per square inch than the Poly, but by less than 5%. The Poly provided more power because they were larger, e.g. had more square inches. My take on this is go with the cheapest (Poly) unless they are just too large to fit your area of application.
wa8yxm wrote:
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.
FWIW, this assumed what is ‘well known’ may seem to be more than a minor revelation to the many folks who have read repeatedly that mono are more efficient than poly, and come typically at a premium over poly - but admittedly the world seems a bit Orwellian today - lolpianotuna wrote:
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.
Exactly, just making light of an ole adage/axiom/maxim!- 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"????? 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.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...- 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. 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- 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.
