pvlib.solarposition.solar_zenith_analytical(latitude, hourangle, declination)[source]

Analytical expression of solar zenith angle based on spherical trigonometry.


The analytic form neglects the effect of atmospheric refraction.

  • latitude (numeric) – Latitude of location in radians.

  • hourangle (numeric) – Hour angle in the local solar time in radians.

  • declination (numeric) – Declination of the sun in radians.


zenith (numeric) – Solar zenith angle in radians.


[1] J. A. Duffie and W. A. Beckman, “Solar Engineering of Thermal Processes, 3rd Edition” pp. 14, J. Wiley and Sons, New York (2006)

[2] J. H. Seinfeld and S. N. Pandis, “Atmospheric Chemistry and Physics” p. 132, J. Wiley (1998)

[3] Daryl R. Myers, “Solar Radiation: Practical Modeling for Renewable Energy Applications”, p. 5 CRC Press (2013)

Wikipedia: Solar Zenith Angle

PVCDROM: Sun’s Position