pvlib.solarposition.declination_cooper69¶
-
pvlib.solarposition.
declination_cooper69
(dayofyear)[source]¶ Solar declination from Duffie & Beckman and attributed to Cooper (1969).
See 1 for details.
Warning
Return units are radians, not degrees.
Declination can be expressed using either sine or cosine:
\[\delta = 23.45 \sin \left( \frac{2 \pi}{365} \left(n_{day} + 284 \right) \right) = -23.45 \cos \left( \frac{2 \pi}{365} \left(n_{day} + 10 \right) \right)\]- Parameters
dayofyear (numeric) –
- Returns
declination (radians) (numeric) – Angular position of the sun at solar noon relative to the plane of the equator, approximately between +/-23.45 (degrees).
References
- 1
J. A. Duffie and W. A. Beckman, “Solar Engineering of Thermal Processes, 3rd Edition” pp. 13-14, J. Wiley and Sons, New York (2006)
- 2
J. H. Seinfeld and S. N. Pandis, “Atmospheric Chemistry and Physics” p. 129, J. Wiley (1998)
- 3
Daryl R. Myers, “Solar Radiation: Practical Modeling for Renewable Energy Applications”, p. 4 CRC Press (2013)
See also