PV array question on house roof with pvsyst

SH YangSH Yang Registered Users Posts: 9

I am doing a kind of project with pvsyst in order to complete pv system on the house roof.
I got a performance ratio at 0.8 (4kwh) and shading factor 0.976.
(I think shading factor is the most important to consider postions or size of the pv array, so I just focused on the shading factor to decide position and design on pvsyst.)

Actaully, there is a chimney like the attached image, so there are two choices to put pv panels on the roof.
One is just one rectangular plane and two rectangular planes (left side and right side from the chimney)
However, I still do not know what is the difference or dis or advantage of putting one or two planes on the roof,
since I could get almost same pr and shading factor..
I just assume that building only one plane might be easy to clean and maintain..
Am I right??

Attachment not found.


  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: PV array question on house roof with pvsyst

    welcome, can you dd the North Arrow to you picture? this is needed to visualize the orientation of the panel arrays.
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  • BB.BB. Super Moderators, Administrators Posts: 31,783 admin
    Re: PV array question on house roof with pvsyst

    Are you doing this in the UK?

    We are starting to get some posts here about new fire codes in the US that to help firemen better access the roof and panels (and cut smoke vents). Adding space for walkways around the array, etc.

    In general, the warnings where about installing arrays with different orientations and/or roof mount+ground mount (different cooling) and running to the same GT inverter / MPPT charge controller (different Vmp-array voltages because of different conditions).

    Panels separated in space, but still with the same basic mounting conditions should be otherwise fine.

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  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: PV array question on house roof with pvsyst

    When part of a string of panels is shaded there is severe effect on output of the entire string. If the shading occurs early or late in the day it is not so important because there is not much power production then anyway. If that chimney (or anything else) will be casting any shadows during the middle of the day, you might want to consider using a microinverter system. In a microinverter system each panel is its own string and shading of one panel does not effect the others.
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