Quantifying Solar PV Variability at Multiple Timescales for Power Systems Studies

This paper presents two metrics - Fourier coefficients of irradiation ramps and average irradiation ramps to quantify solar photovoltaic (PV) variability at multiple temporal scales to improve the accuracy of power systems studies under high solar PV penetrations. The key findings based on these metrics are: (i) a single sensor significantly exaggerates the variability of a solar PV power plant at seconds to 1-minute temporal resolution, but it can be fairly accurate at lower than 1-minute resolutions, (ii) at each 1-minute and lower temporal resolution, largest solar irradiation ramps appear to be independent of the geographical location, and (iii) significant reduction in solar PV plant variability over a region with multiple plants is possible at all temporal scales, but more high temporal resolution data is needed to conclusively quantify the reduction.