solpos

solpos.solpos(year, month, day, hour, minute, second, timezone, *, latitude, longitude, interval=0, aspect=180.0, press=1013.0, sbwid=7.6, sbrad=31.7, sbsky=0.04, solcon=1367.0, temp=15.0, tilt=0.0)[source]

Computes the solar position and intensity from time and place.

The underlying posdata pdat->function struct is set to S_ALL meaning all possible parameters are calculated using the defaults or the user defined values.

Parameters:

  • year (int) – 4-digit year (2-digit years are NOT allowed)

  • month (int) – Month number (Jan = 1, Feb = 2, etc.)

  • day (int) – Day of month (May 27 = 27, etc.)

  • hour (int) – Hour of day, 0 - 24. (Time 24:00:00 is treated internally as time 00:00:00 of the following day.)

  • minute (int) – Minute of hour, 0 - 59

  • second (int) – Second of minute, 0 - 59

  • timezone (float) – Time zone, east (west negative). USA: Mountain = -7, Central = -6, etc.

  • latitude (float) – Latitude, degrees north (south negative)

  • longitude (float) – Longitude, degrees east (west negative)

  • interval (int) – Interval of a measurement period in seconds. Forces solpos to use the time and date from the interval midpoint. The input time (hour, minute, and second) is assumed to be the END of the measurement interval (right labelled) (default: 0.0)

  • aspect (float) – Azimuth of panel surface in degrees (direction it faces) N=0, E=90, S=180, W=270. (default: 180.0)

  • press (float) – Surface pressure, millibars, used for refraction correction and ampress (default: 1013.0)

  • sbwid (float) – Shadow-band width (cm) (default: 7.6)

  • sbrad (float) – Shadow-band radius (cm) (default: 31.7)

  • sbsky (float) – Shadow-band sky factor (-1 - 1) (default: 0.04)

  • solcon (float) – Solar constant (NREL uses 1367 W/m²) (default: 1367.0)

  • temp (float) – Ambient dry-bulb temperature, degrees C, used for refraction correction (default: 15.0)

  • tilt (float) – Degrees tilt from horizontal of panel (-180 - 180) (default: 0.0)

Return type:

solpos.SolposResult

Returns:

A solpos.SolposResult() object with all parameters that SOLPOS is able to calculate (including all input parameters)

class solpos.SolposResult[source]

Container for the results returned by solpos.solpos().

Parameters:

  • year (int) – 4-digit year

  • month (int) – Month number (Jan = 1, Feb = 2, etc.)

  • day (int) – Day of month (May 27 = 27, etc.)

  • hour (int) – Hour of day, 0 - 24. (Time 24:00:00 is treated internally as time 00:00:00 of the following day.)

  • minute (int) – Minute of hour, 0 - 59

  • second (float) – Second of minute, 0 - 59

  • timezone (float) – Time zone, east (west negative). USA: Mountain = -7, Central = -6, etc.

  • latitude (float) – Latitude, degrees north (south negative)

  • longitude (float) – Longitude, degrees east (west negative)

  • interval (int) – Interval of a measurement period in seconds

  • aspect (float) – Azimuth of panel surface in degrees (direction it faces) N=0, E=90, S=180, W=270.

  • press (float) – Surface pressure, millibars

  • sbwid (float) – Shadow-band width (cm)

  • sbrad (float) – Shadow-band radius (cm)

  • sbsky (float) – Shadow-band sky factor (-1 - 1)

  • solcon (float) – Solar constant (W/m²)

  • temp (float) – Ambient dry-bulb temperature, degrees C

  • tilt (float) – Degrees tilt from horizontal of panel (-180 - 180)

  • amass (float) – Relative optical airmass

  • ampress (float) – Pressure-corrected airmass

  • azim (float) – Solar azimuth angle (degrees): N=0, E=90, S=180,W=270

  • cosinc (float) – Cosine of solar incidence angle on panel

  • coszen (float) – Cosine of refraction corrected solar zenith angle

  • dayang (float) – Day angle \(\frac{daynum * 360}{year\_length}\), degrees

  • declin (float) – Declination-zenith angle of solar noon at equator degrees NORTH

  • eclong (float) – Ecliptic longitude, degrees

  • ecobli (float) – Obliquity of ecliptic

  • ectime (float) – Time of ecliptic calculations

  • elevetr (float) – Solar elevation, no atmospheric correction (= ETR)

  • elevref (float) – Solar elevation angle, degrees from horizon, refracted

  • eqntim (float) – Equation of time (TST - LMT), minutes

  • erv (float) – Earth radius vector(multiplied to solar constant)

  • etr (float) – Extraterrestrial (top-of-atmosphere) W/m² global horizontal solar irradiance

  • etrn (float) – Extraterrestrial (top-of-atmosphere) W/m² direct normal solar irradiance

  • etrtilt (float) – Extraterrestrial (top-of-atmosphere) W/m² global irradiance on a tilted surface

  • gmst (float) – Greenwich mean sidereal time, hours

  • hrang (float) – Hour angle–hour of sun from solar noon degrees WEST

  • julday (float) – Julian Day of 1 JAN 2000 minus 2,400,000 days (in order to regain single precision)

  • lmst (float) – Local mean sidereal time, degrees

  • mnanom (float) – Mean anomaly, degrees

  • mnlong (float) – Mean longitude, degrees

  • rascen (float) – Right ascension, degrees

  • press – Surface pressure, millibars, used for refraction correction and ampress

  • prime (float) – Factor that normalizes \(K_t\), \(K_n\), etc.

  • sbcf (float) – Shadow-band correction factor

  • sbwid – Shadow-band width (cm)

  • sbrad – Shadow-band radius (cm)

  • sbsky – Shadow-band sky factor

  • solcon – Solar constant, W/m²

  • ssha (float) – Sunset(/rise) hour angle, degrees

  • sretr (float) – Sunrise time, minutes from midnight, local, without refraction

  • ssetr (float) – Sunset time, minutes from midnight, local, without refraction

  • temp – Ambient dry-bulb temperature, degrees C, used for refraction correction

  • tilt – Degrees tilt from horizontal of panel

  • tst (float) – True solar time, minutes from midnight

  • tstfix (float) – True solar time - local standard time

  • unprime (float) – Factor that denormalizes \(K_t'\), \(K_n'\), etc.

  • utime (float) – Universal (Greenwich) standard time

  • zenetr (float) – Solar zenith angle, no atmospheric correction (= ETR)

  • zenref (float) – Solar zenith angle, degrees from zenith, refracted.