pvlib.irradiance.reindl#
- pvlib.irradiance.reindl(surface_tilt, surface_azimuth, dhi, dni, ghi, dni_extra, solar_zenith, solar_azimuth, return_components=False)[source]#
Determine the diffuse irradiance from the sky on a tilted surface using the Reindl (1990) model.
The Reindl (1990) model [1] [2] determines the diffuse irradiance from the sky on a tilted surface using the surface tilt angle, surface azimuth angle, diffuse horizontal irradiance, direct normal irradiance, global horizontal irradiance, extraterrestrial normal irradiance, sun zenith angle, and sun azimuth angle.
- Parameters:
surface_tilt (numeric) – Panel tilt from the horizontal. See surface_tilt. [°]
surface_azimuth (numeric) – Panel azimuth. See surface_azimuth. [°]
dhi (numeric) – Diffuse horizontal irradiance, see dhi. [Wm⁻²]
dni (numeric) – Direct normal irradiance, see dni. [Wm⁻²]
ghi (numeric) – Global horizontal irradiance, see ghi. [Wm⁻²]
dni_extra (numeric) – Extraterrestrial normal irradiance, see dni_extra. [Wm⁻²]
solar_zenith (numeric) – Solar apparent (refraction-corrected) zenith angles See solar_zenith. [°]
solar_azimuth (numeric) – Solar azimuth angles. See solar_azimuth. [°]
return_components (bool, default
False) – IfFalse,poa_sky_diffuseis returned. IfTrue,diffuse_componentsis returned.
- Returns:
numeric, dict, or DataFrame – Return type controlled by
return_componentsargument. Ifreturn_components=False,poa_sky_diffuseis returned. Ifreturn_components=True,diffuse_componentsis returned.poa_sky_diffuse (numeric) – The sky diffuse component of irradiance on a tilted plane. [Wm⁻²]
diffuse_components (dict (array input) or DataFrame (Series input)) –
- Keys/columns are:
poa_sky_diffuse: The sky diffuse component of irradiance on a tilted plane. [Wm⁻²]
poa_isotropic: The portion of sky diffuse irradiance on a tilted plane from the isotropic sky dome. [Wm⁻²]
poa_circumsolar: The portion of sky diffuse irradiance on a tilted plane from the circumsolar region. [Wm⁻²]
poa_horizon: The portion of sky diffuse irradiance on a tilted plane from the horizon. [Wm⁻²]
Notes
The Reindl (1990) model for the sky diffuse irradiance, \(I_d\), is as follows:
\[I_{d} = DHI \left(A \cdot R_b + (1 - A) \left(\frac{1 + \cos\beta}{2}\right) \left(1 + \sqrt{\frac{BHI}{GHI}} \sin^3(\beta/2)\right) \right).\]\(DHI\), \(BHI\), and \(GHI\) are the diffuse horizontal, beam (direct) horizontal and global horizontal irradiances, respectively. \(A\) is the anisotropy index, which is the ratio of the direct normal irradiance to the direct extraterrestrial irradiation, \(R_b\) is the projection ratio, which is defined as the ratio of the cosine of the angle of incidence (AOI) to the cosine of the zenith angle, and \(\beta\) is the tilt angle of the array.
Implementation is based on Loutzenhiser et al. (2007) [3], Equation 8. The beam and ground reflectance portion of the equation have been removed, therefore the model described here generates ONLY the diffuse radiation from the sky, circumsolar, and horizon brightening, so the form of the equation varies slightly from Equation 8 in [3].
For clarity, the horizon component in
reindlcorresponds to the term added on top of thehaydaviesformulation, on whichreindlbuilds.References