Review of Canadian Solar 305 W - 72 cell Poly-crystalline Solar Panels

23 March 2015

Introduction:

I am a retired Professional Engineer with an Ontario Microfit solar panel system.  I try to review various solar products to give the general public some feed back on the different panels out there.

First Impressions:

The panels arrived over 12 days ago, all in good looking condition.  The first thing that I noticed was a center support bar that added point load support in the center of the panel.  This panels look professionally made with screws in the ends holding the rails together.  The backing material is most likely EVA which may or may not give us some problems in the future.  I would have preferred Kynar or equivalent backing material.  They are warrantied  for 25 years.  It doesn't cover installation or shipping.  You can read my other blogs on the best backing material to use.

We have some 300 W. Heliene {H} Panels which we like, one mono Silfab and the rest 250 W poly.  The CS panels have been on the roof for over 10 days so the initial burn in should be over.  The Heliene panels are about 1 year old.

Sunday was finally a great solar day with very few clouds.  I positioned 3 CS and 6 H panels on the south roof and 3 CS panels with 2 H panels on the West roof for comparison.  Our roof pitch is only 22.5 deg so we are about 20 deg from perpendicular at this time of year.  I observed a peak of 304 W from one of(t)he CS while one H panel produced 270 W located at the roof line in the best location. All of the CS panels performed well and close in output to each other.

Results:

The Canadian Solar (CS) panels harvested as follows:  South:  2.21, 2.05, 2.15 kW. 

                                                                                         West: 1.68, 1.62 1.53 kW (first 2 panels get more sun as the sun slowly moves around our array in the am.)

 Heliene (H)  harvested:  South 1.96 (best position), 1.94, 1.91 kW

                                 West: 1.35, 1.4 kW

Discussion:

As you can see, the new CS panels blew away the H  panels.  Compared to the 300 W H panels, the 305 W CS panels are making about 330 W.  The H panels compare well with our other 250 W poly panels.  The improved performance is due to the fact that the CS panels are using the next generation poly-crystalline materials (according to my seller).  These panels are truly rated on the PTCUSA standard as all panels should be.  That would be the H panels at around 270 W(300 W STC) and the CS at 305 W (PTCUSA).

The low light harvesting of these new CS panels is outstanding.  The average output on south is 2.137 kW and for H is 1.937 kW  Or CS averages 10.3 % better on South exposure and 13% on West exposure.  This may decrease in time but that equates to a 330 W equivalent for South.  I will repose this in one month.  The day was cold which helps to keep the sky clear and the panels working great.  I want all of my panels to do this great.  For fixed roof applications, these are the best that we have seen  If other are also using the next generation poly-crystalline material, expect equal results. It is my understanding that CS have 3 plants that make their own crystalline.  That is a big advantage.  I have been waiting to see some type of improvement in poly for the past 3 years.  Off axis light is IMHO normal for all panels, especially east and west orientated.  IMHO, for most applications mono is out, it is too directional except for trackers.

The peak power production, low light and total kW harvested is just fantastic.  They are exceeding all of my expectations except for the backing materials.  You may be able to get a different backing material at a slightly higher price.

Poly-crystalline panels are generally the preferred type of panels except possibly when using a solar tracker.  So for fixed roof installations, the low light properties are outstanding for these CS panels.  The CS panels on the west roof produced the same amount of harvesting as did most of our 250 W south facing panels.  

 I can truthfully say: "Just loving it".  They help us even more to do our part in reducing our CO 2 foot print.

BUY Canadian Solar CS6X-305P None Ontario Poly Panels

All power levels from the SolarEdge monitoring system.

Thanks for dropping by.

May 11 2015 UPDATE:  Still seeing the same great results compared with existing panels.  WOW.  IMHO these are the best solar panels that I have ever seen.  Sept 2015 still going strong - Loving It.

On a ROI basis they are the best solar panels currently on the market.

NOTE: You can't buy Sunpower panels and they have a huge up front cost and are tied in with a terrible racking system and an outdated inverter system for most applications  SP have the best cell but it is the total system that counts and ROI.

Currently Strongly Recommended Sept 2015