Describe the bug
pvlib python implements the Young and Irvine 1967 model as:
elif 'youngirvine1967' == model:
am = ((1.0 / np.cos(zenith_rad)) *
(1 - 0.0012*((1.0 / np.cos(zenith_rad)) ** 2) - 1))The published formula is
am = sec(z) * (1 - 0.0012 * (sec(z)^2 - 1))
See http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1967AJ.....72..945Y&db_key=AST&page_ind=3&plate_select=NO&data_type=GIF&type=SCREEN_GIF&classic=YES
If you squint very hard you might notice that pvlib python's implementation is equivalent to
am = sec(z) * (1 - 0.0012 * sec(z)^2 - 1)
Versions:
pvlib.__version__: 0.5.2. I probably broke it when cleaning up code in the 0.1-0.2 era.
Additional context
Discovered when implementing #158. Write good unit tests! I'll make a pr with a fix soon.
Describe the bug
pvlib python implements the Young and Irvine 1967 model as:
The published formula is
See http://adsbit.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1967AJ.....72..945Y&db_key=AST&page_ind=3&plate_select=NO&data_type=GIF&type=SCREEN_GIF&classic=YES
If you squint very hard you might notice that pvlib python's implementation is equivalent to
Versions:
pvlib.__version__: 0.5.2. I probably broke it when cleaning up code in the 0.1-0.2 era.Additional context
Discovered when implementing #158. Write good unit tests! I'll make a pr with a fix soon.