pvanalytics.metrics.variability_index#
- pvanalytics.metrics.variability_index(measured, clearsky, freq=None)#
Calculate the variability index.
- Parameters
measured (Series) – Time series of measured GHI. [W/m2]
clearsky (Series) – Time series of the expected clearsky GHI. [W/m2]
freq (pandas datetime offset, optional) – Aggregation period (e.g. ‘D’ for daily). If not specified, the variability index for the entire time series will be returned.
- Returns
vi – The calculated variability index
- Return type
Series or float
References
- 1
Stein, Joshua, Hansen, Clifford, and Reno, Matthew J. THE VARIABILITY INDEX: A NEW AND NOVEL METRIC FOR QUANTIFYING IRRADIANCE AND PV OUTPUT VARIABILITY. SAND2012-2088C, World Renewable Energy Forum, 2012.
