Hello again,
A couple years ago I posed a question about horizon shading to the forum:
sam.nrel.gov/forum/forum-general/2204
I received a very helpful and prompt answer from Steve, however I still have some questions about calculating the diffuse fraction.
I went to the lines Steve referenced in his answer, but I think there must be a discrepancy between his version of the .cpp file and the one I'm seeing because the lines don't seem to contain the code Steve describes. Regardless, I don't quite have the background in C++ to fully understand the code. Particularly, I don't see how array tilt is included in the calculation of the diffuse shading factors.
Could you please provide the equations in a non C++ format one would use to calculate the diffuse shading factor, i.e, the parameter labeled
in the
module of the SDKTool?
Again, I understand conceptually that this is the ratio of the sky seen by the array (total skydome - what's obstructed by the horizon - what is not seeable because of the array's tilt) / the total area of the skydome.
thanks for your patience,
Joe
