solarspatialtools.stats.darr

solarspatialtools.stats.darr(series, tau=1, moving_avg=True, pct=False)

Compute the Daily Aggregate Ramp Rate as described by Van Haaren et al. [1]

The DARR represents the sum of all possible ramp rates, and according to the original source, could be normalized as a percent of STC irradiance.

The original source computes this quantity using the GHI, but we offer the possibility of computing it for clear sky index.

Parameters

seriespandas.Series

a time series for which to calculate the Variability Score

taunumeric, default 1

The number of timesteps for the increment calculation. series must use a temporal index to use a dt greater than 1.

moving_avgbool, default True

When tau specified with a value different from 1, should the timeseries be resampled via moving avg to the frequency of tau for computation?

pctbool, default False

should we scale the score as a percent of 1000 W/m2 (0-100%)?

Returns

darrnumeric

The value of the metric

[1] R. van Haaren, M. Morjaria, and V. Fthenakis, “Empirical assessment of short-term variability from utility-scale solar PV plants,” Progress in Photovoltaics: Research and Applications 22, 548–559 (2014), https://www.researchgate.net/publication/261603714_Empirical_assessment_of_short-term_variability_from_utility-scale_solar_PV_plants