pvperfsolar performance modeling

Reference

API field

Solar position method

Which algorithm computes the position of the sun

What it is

Selects the algorithm that computes the height and azimuth of the sun at every timestep.

Typical values and how to get it

Chosen on the Model tab.

Values

PVsyst 8 ephemeris = pvsyst (default): PVsyst 8's simplified ephemeris: the declination once per day, at 12:00 UT of the date, from the United States Naval Observatory's approximate formulas, and a Fourier-series equation of time · NREL SPA = spa: NREL's Solar Position Algorithm (Reda and Andreas), with refraction, accurate to 0.0003° · Michalsky 1988 = michalsky: the Astronomical Almanac's approximate algorithm (Michalsky 1988), accurate to 0.01° · NREL SPA (SSC application) = spa_ssc: the Solar Position Algorithm as NREL's SSC codes it, with SG2 terms, the weather's pressure and temperature in the refraction, and sunrise and sunset at −0.8333° setting the lit timesteps

References

  1. United States Naval Observatory, Approximate Solar Coordinates (aa.usno.navy.mil)
  2. Reda & Andreas 2008, Solar Position Algorithm for Solar Radiation Applications, NREL/TP-560-34302
  3. Michalsky 1988, The Astronomical Almanac's algorithm for approximate solar position (1950–2050), Solar Energy 40(3) 227–235

API

site.sun_model