pvlib.irradiance.clearsky_index(ghi, clearsky_ghi, max_clearsky_index=2.0)[source]#

Calculate the clearsky index.

The clearsky index is the ratio of global to clearsky global irradiance. Negative and non-finite clearsky index values will be truncated to zero.

  • ghi (numeric) – Global horizontal irradiance in W/m^2.

  • clearsky_ghi (numeric) – Modeled clearsky GHI

  • max_clearsky_index (numeric, default 2.0) – Maximum value of the clearsky index. The default, 2.0, allows for over-irradiance events typically seen in sub-hourly data.


clearsky_index (numeric) – Clearsky index