Power output fluctuations in large scale pv plants: One year observations with one second resolution and a derived analytic model

Abstract

The variable nature of the irradiance can produce significant fluctuations in the power generated by large grid-connected photovoltaic (PV) plants. Experimental 1 s data were collected throughout a year from six PV plants, 18MWp in total. Then, the dependence of short (below lOmin) power fluctuation on PV plant size has been investigated. The analysis focuses on the study of fluctuation frequency as well as the maximum fluctuation value registered. An analytic model able to describe the frequency of a given fluctuation for a certain day is proposed.

Analysis and synthesis of the variability of irradiance and PV power time series with the wavelet transform

“…This description is consistent with the formulation of the probability of uctuation level with a decaying exponential model published in [2].…”

“…This equation works under the assumption that the incident irradiance is the same simultaneously over the whole PV generator plane. As the reference [2] has shown, this supposition is not true for large PV generators. A plausible approximation is to model the behaviour of the plant around two assumptions:…”

Local short-term variability in solar irradiance

“…size (Dyreson et al, 2014;Lave et al, 2012;Marcos et al, 2011b;van Haaren et al, 2014). Furthermore, spatial autocorrelation structures and decorrelation length scales of increments in irradiance and clear-sky index (i.e., irradiance normalized to clear-sky conditions), and PV power output have also been studied for a range of spatial scales and increment values (Arias-Castro et al, 2014;Elsinga and van Sark, 2014;Hinkelman, 2013;Hoff and Perez, 2012;Mills, 2010;Perez et al, 2012;Perpiñán et al, 2013).…”

Power output fluctuations in large PV plants

“…However, for ∆t=600s, coefficient c is equal to 0.02 which supports the idea that, for these sampling times, the plant size is not a smoothing factor for the fluctuations. A more detailed and supplementary account of the results shown in this and the previous section can be found in [8].…”