# Defining tilted Photovoltaic panels on flat roof and attic roof

Currently I am defining PV on roof using Shading:Site:Detailed to input the coordinates of my shading site, which is my entire roof area(4 vertex coordinates), but the problem is I do not know how to add tilt angle for the PV panel.

Can I use one of the vertex coordinates I defined in Shading:Site:Detailed as the starting coordinate for Shading:Building? In this case which vertex should I use as my starting coordinate? In addition,what value should I put for length and height under Shading:building? Are the height and length the same as the depth and length of the solar module?

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I'm not sure I understand what's your problem. Can't you draw a Shading:Site:Detailed surface that is titled and use that as your surface for your panels?

( 2017-02-23 02:28:50 -0500 )edit

I used Shading:Site:Detaied to define my shading surface for the PV.Are the coordinates of the tilted surface to be defined with the respect to the roof or with the respect to the origin, if global geometry rules have been defined as world?But then the z coordinates in the example file GeneratorwithPV was 0 for some of the panel shading surfaces,which didn't make sense.

( 2017-02-27 22:00:41 -0500 )edit

I defined a tilted surface suing Shading:site:detailed for the panels.But are the coordinates of the tilted surface with respect to the roof or with respect to building origin,if global geometry rules coordinate system have been defined as relative? Also, I read that shading surfaces have to defined such that we are facing it from the inside and surfaces of the building such that we are facing it from the outside.Does this apply for attached shading surfaces like PV array as well?

( 2017-02-27 22:01:26 -0500 )edit

Have you tried using either the OpenStudio or Legacy OpenStudio Sketchup plugins in order to visualize your IDF file and draw stuff? I feel like it would really help you to see what's what.

( 2017-02-28 04:29:20 -0500 )edit