geodata.pv.solar_position.SolarPosition

geodata.pv.solar_position.SolarPosition(ds)

Compute solar azimuth and altitude

Solar altitude errors are up to 1.5 deg during sun-rise and set, but at 0.05-0.1 deg during daytime.

References

[1] Michalsky, J. J., The astronomical almanac’s algorithm for approximate solar position (1950–2050), Solar Energy, 40(3), 227–235 (1988). [2] Sproul, A. B., Derivation of the solar geometric relationships using vector analysis, Renewable Energy, 32(7), 1187–1205 (2007). [3] Kalogirou, Solar Energy Engineering (2009).

More accurate algorithms would be

[4] I. Reda and A. Andreas, Solar position algorithm for solar radiation applications. Solar Energy, vol. 76, no. 5, pp. 577-589, 2004. [5] I. Reda and A. Andreas, Corrigendum to Solar position algorithm for solar radiation applications. Solar Energy, vol. 81, no. 6, p. 838, 2007. [6] Blanc, P., & Wald, L., The SG2 algorithm for a fast and accurate computation of the position of the sun for multi-decadal time period, Solar Energy, 86(10), 3072–3083 (2012).

The unfortunately quite computationally intensive SPA algorithm [4,5] has been implemented using numba or plain numpy for a single location at pvlib/pvlib-python.