- pvlib.bifacial.infinite_sheds.get_irradiance_poa(surface_tilt, surface_azimuth, solar_zenith, solar_azimuth, gcr, height, pitch, ghi, dhi, dni, albedo, model='isotropic', dni_extra=None, iam=1.0, npoints=100, vectorize=False)[source]#
Calculate plane-of-array (POA) irradiance on one side of a row of modules.
The infinite sheds model  assumes the PV system comprises parallel, evenly spaced rows on a level, horizontal surface. Rows can be on fixed racking or single axis trackers. The model calculates irradiance at a location far from the ends of any rows, in effect, assuming that the rows (sheds) are infinitely long.
POA irradiance components include direct, diffuse and global (total). Irradiance values are reduced to account for reflection of direct light, but are not adjusted for solar spectrum or reduced by a module’s bifaciality factor.
surface_tilt (numeric) – Tilt of the surface from horizontal. Must be between 0 and 180. For example, for a fixed tilt module mounted at 30 degrees from horizontal, use
surface_tilt=30to get front-side irradiance and
surface_tilt=150to get rear-side irradiance. [degree]
surface_azimuth (numeric) – Surface azimuth in decimal degrees east of north (e.g. North = 0, South = 180, East = 90, West = 270). [degree]
solar_zenith (numeric) – Refraction-corrected solar zenith. [degree]
solar_azimuth (numeric) – Solar azimuth. [degree]
gcr (float) – Ground coverage ratio, ratio of row slant length to row spacing. [unitless]
height (float) – Height of the center point of the row above the ground; must be in the same units as
pitch (float) – Distance between two rows; must be in the same units as
ghi (numeric) – Global horizontal irradiance. [W/m2]
dhi (numeric) – Diffuse horizontal irradiance. [W/m2]
dni (numeric) – Direct normal irradiance. [W/m2]
albedo (numeric) – Surface albedo. [unitless]
model (str, default 'isotropic') – Irradiance model - can be one of ‘isotropic’ or ‘haydavies’.
dni_extra (numeric, optional) – Extraterrestrial direct normal irradiance. Required when
iam (numeric, default 1.0) – Incidence angle modifier, the fraction of direct irradiance incident on the surface that is not reflected away. [unitless]
npoints (int, default 100) – Number of discretization points for calculating integrated view factors.
vectorize (bool, default False) – If True, vectorize the view factor calculation across
surface_tilt. This increases speed with the cost of increased memory usage.
output (dict or DataFrame) – Output is a DataFrame when input ghi is a Series. See Notes for descriptions of content.
pitchmust have the same unit.
poa_global: total POA irradiance. [W/m^2]
poa_diffuse: total diffuse POA irradiance from all sources. [W/m^2]
poa_direct: total direct POA irradiance. [W/m^2]
poa_sky_diffuse: total sky diffuse irradiance on the plane of array. [W/m^2]
poa_ground_diffuse: total ground-reflected diffuse irradiance on the plane of array. [W/m^2]
Mikofski, M., Darawali, R., Hamer, M., Neubert, A., and Newmiller, J. “Bifacial Performance Modeling in Large Arrays”. 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC), 2019, pp. 1282-1287. DOI: 10.1109/PVSC40753.2019.8980572.