Calculate the solar position using the C implementation of the NREL
SPA code.
The source files for this code are located in ‘./spa_c_files/’, along with
a README file which describes how the C code is wrapped in Python.
Due to license restrictions, the C code must be downloaded seperately
and used in accordance with it’s license.
This function is slower and no more accurate than spa_python().
temperature (float, default 12) – Temperature in C
delta_t (float, default 67.0) – Difference between terrestrial time and UT1.
USNO has previous values and predictions [3].
raw_spa_output (bool, default False) – If true, returns the raw SPA output.
Returns:
DataFrame – The DataFrame will have the following columns:
elevation,
azimuth,
zenith,
apparent_elevation,
apparent_zenith.
References
Note: The timezone field in the SPA C files is replaced with
time_zone to avoid a nameclash with the function __timezone that is
redefined by Python>=3.5. This issue is
Python bug 24643.