pvlib.irradiance.perez_driesse

pvlib.irradiance.perez_driesse(surface_tilt, surface_azimuth, dhi, dni, dni_extra, solar_zenith, solar_azimuth, airmass=None, return_components=False)

Determine diffuse irradiance from the sky on a tilted surface using the continuous Perez-Driesse model.

The Perez-Driesse model [1] is a reformulation of the 1990 Perez model [2] that provides continuity of the function and of its first derivatives. This is achieved by replacing the look-up table of coefficients with quadratic splines.

Parameters:

• surface_tilt (numeric) – Surface tilt angles in decimal degrees. surface_tilt must be >=0 and <=180. The tilt angle is defined as degrees from horizontal (e.g. surface facing up = 0, surface facing horizon = 90)

• surface_azimuth (numeric) – Surface azimuth angles in decimal degrees. surface_azimuth must be >=0 and <=360. The azimuth convention is defined as degrees east of north (e.g. North = 0, South=180 East = 90, West = 270).

• dhi (numeric) – Diffuse horizontal irradiance. [Wm⁻²] dhi must be >=0.

• dni (numeric) – Direct normal irradiance. [Wm⁻²] dni must be >=0.

• dni_extra (numeric) – Extraterrestrial normal irradiance. [Wm⁻²]

• solar_zenith (numeric) – apparent (refraction-corrected) zenith angles in decimal degrees. solar_zenith must be >=0 and <=180.

• solar_azimuth (numeric) – Sun azimuth angles in decimal degrees. solar_azimuth must be >=0 and <=360. The azimuth convention is defined as degrees east of north (e.g. North = 0, East = 90, West = 270).

• airmass (numeric, optional) – Relative (not pressure-corrected) airmass values. If airmass is a DataFrame it must be of the same size as all other DataFrame inputs. The kastenyoung1989 airmass calculation is used internally and is also recommended when pre-calculating airmass because it was used in the original model development.

• return_components (bool (optional, default=False)) – Flag used to decide whether to return the calculated diffuse components or not.

Returns:

• numeric, OrderedDict, or DataFrame – Return type controlled by return_components argument. If return_components=False, sky_diffuse is returned. If return_components=True, diffuse_components is returned.

• sky_diffuse (numeric) – The sky diffuse component of the solar radiation on a tilted surface.

• diffuse_components (OrderedDict (array input) or DataFrame (Series input)) –

  Keys/columns are:

  • sky_diffuse: Total sky diffuse

  • isotropic

  • circumsolar

  • horizon

Notes

The Perez-Driesse model can be considered a plug-in replacement for the 1990 Perez model using the 'allsitescomposite1990' coefficient set. Deviations between the two are very small, as demonstrated in [1]. Other coefficient sets are not supported because the 1990 set is based on the largest and most diverse set of empirical data.

References

[1] (1,2)

Driesse, A., Jensen, A., Perez, R., 2024. A Continuous form of the Perez diffuse sky model for forward and reverse transposition. Solar Energy vol. 267. DOI: 10.1016/j.solener.2023.112093

[2]

Perez, R., Ineichen, P., Seals, R., Michalsky, J., Stewart, R., 1990. Modeling daylight availability and irradiance components from direct and global irradiance. Solar Energy 44 (5), 271-289.

See also

perez, isotropic, haydavies, klucher, reindl, king

Examples using pvlib.irradiance.perez_driesse

Modelling shading losses in modules with bypass diodes

Modelling shading losses in modules with bypass diodes