July 17, 20233 yr For what it's worth I just completed putting 6x 455W panels on a SE roof. That is 2700kwp Todays max was 950W in pure sun. You better off installing less panels but making sure the orientation and pitch is your best possible option.
July 17, 20233 yr Author I really appreciate the info everyone, what I will do is climb up and use the compass app on the phone directly on the 4x 450 panels that are already installed. Then I will provide feed back. On the small section facing NW what if I can only fit 5 panels what size should I look at. Would 595w be okay due to space constraints. Will do the compass thing and post.
July 17, 20233 yr 26 minutes ago, Greglsh said: I really appreciate the info everyone, what I will do is climb up and use the compass app on the phone directly on the 4x 450 panels that are already installed. Then I will provide feed back. On the small section facing NW what if I can only fit 5 panels what size should I look at. Would 595w be okay due to space constraints. Will do the compass thing and post. @GreglshYou don't need to climb on the roof to determine the roof orientation stand on the ground with your back faced to the roof then align the phone according to roof direction and measure.
July 17, 20233 yr 5 minutes ago, TaliaB said: @GreglshYou don't need to climb on the roof to determine the roof orientation stand on the ground with your back faced to the roof then align the phone according to roof direction and measure. Good advice. One only needs like the North direction to know all the different roof directions. Edited July 17, 20233 yr by Scorp007
July 17, 20233 yr 3 hours ago, Chris_S said: For what it's worth I just completed putting 6x 455W panels on a SE roof. That is 2700kwp Todays max was 950W in pure sun. You better off installing less panels but making sure the orientation and pitch is your best possible option. While you did this estimate may be you can with the same panels calculate what 6 x east= 6 x west= For if one had the 2 in parallel into 1 x MPPT.
July 17, 20233 yr Author Just thought I would show this solar production chart from my micro-inverters today. So this is in Durban (winter), 4 x 330w panels facing the same way as the small section of roof so almost NW (these are mounted on the tin roof of an out building, problem with these is the 2 panels are now is shade for like 3 hours of the day due to neighbours small trees that have grown. Then 4 x 450w already mounted on the NE roof to which I want to add either another 2 or another 4 panels. So production was 10.48kwh and peak production was at 12:45 at 1.86kw. Then I have attached Feb 2023 monthly usage and production graph, so by adding at least another 4 panels I should almost cover my usage. Edited July 17, 20233 yr by Greglsh
July 17, 20233 yr Author Hi Craig No I have 2 micro inverters that can take 4 panels each, 1 is 1200w and the other is 1500w
July 18, 20233 yr 11 hours ago, Greglsh said: I really appreciate the info everyone, what I will do is climb up and use the compass app on the phone directly on the 4x 450 panels that are already installed. Then I will provide feed back. On the small section facing NW what if I can only fit 5 panels what size should I look at. Would 595w be okay due to space constraints. Will do the compass thing and post. It's all down to the dimensions of your roof. 595W panels are large but if you can fit 4 then great. Just note that these panels are 17A so you would not be able to parallel them on the same mppt
July 18, 20233 yr Author 6 hours ago, Chris_S said: It's all down to the dimensions of your roof. 595W panels are large but if you can fit 4 then great. Just note that these panels are 17A so you would not be able to parallel them on the same mppt I was having a look at the VOC of the 595w panels and it is 41.1v and the VMP is 34.7v, with only 4 panels this is not going to be enough to start the MPPT (150v). Do you use the VOC or do you use the VMP? I see the 545w panels VOC is 49.2v and the VMP is 41.3v. The higher wattage panels keep the voltage low and run higher currents.
July 18, 20233 yr 1 hour ago, Greglsh said: I was having a look at the VOC of the 595w panels and it is 41.1v and the VMP is 34.7v, with only 4 panels this is not going to be enough to start the MPPT (150v). Do you use the VOC or do you use the VMP? I see the 545w panels VOC is 49.2v and the VMP is 41.3v. The higher wattage panels keep the voltage low and run higher currents. Correct. You use Voc as the panels are only under load once the mppt starts. 545W much better idea. All these new panels now have lower voltage and higher amps.
July 18, 20233 yr But even some 545W brands have lower voltage. Even the new hiku6 450W panels are 41Voc and 13Isc So just make sure what you get.
July 18, 20233 yr Author So I did the compass directions this is the small section facing sort of North (347 degrees North) the big section is facing 78 degrees East. Do you use true heading or the one it shows???? Edited July 18, 20233 yr by Greglsh
July 19, 20233 yr 20 hours ago, Greglsh said: So I did the compass directions this is the small section facing sort of North (347 degrees North) the big section is facing 78 degrees East. Do you use true heading or the one it shows???? Those are good directions. Basically East and North. I would focus on those 2 first.
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