pvlib.scaling.wvm

pvlib.scaling.wvm(clearsky_index, positions, cloud_speed, dt=None)[source]

Compute spatial aggregation time series smoothing on clear sky index based on the Wavelet Variability model of Lave et al [1-2]. Implementation is basically a port of the Matlab version of the code [3].

Parameters:
  • clearsky_index (numeric or pandas.Series) – Clear Sky Index time series that will be smoothed.
  • positions (numeric) – Array of coordinate distances as (x,y) pairs representing the easting, northing of the site positions in meters [m]. Distributed plants could be simulated by gridded points throughout the plant footprint.
  • cloud_speed (numeric) – Speed of cloud movement in meters per second [m/s].
  • dt (float, default None) – The time series time delta. By default, is inferred from the clearsky_index. Must be specified for a time series that doesn’t include an index. Units of seconds [s].
Returns:

  • smoothed (numeric or pandas.Series) – The Clear Sky Index time series smoothed for the described plant.
  • wavelet (numeric) – The individual wavelets for the time series before smoothing.
  • tmscales (numeric) – The timescales associated with the wavelets in seconds [s].

References

[1] M. Lave, J. Kleissl and J.S. Stein. A Wavelet-Based Variability Model (WVM) for Solar PV Power Plants. IEEE Transactions on Sustainable Energy, vol. 4, no. 2, pp. 501-509, 2013.

[2] M. Lave and J. Kleissl. Cloud speed impact on solar variability scaling - Application to the wavelet variability model. Solar Energy, vol. 91, pp. 11-21, 2013.

[3] Wavelet Variability Model - Matlab Code: https://pvpmc.sandia.gov/applications/wavelet-variability-model/