Flickering Events in Wind and Solar Power

This paper reports stochastic properties of renewable wind and solar energy resources by studying their conditional probability distribution functions (cpdf) in different time lags. The empirical results are obtained for data of global horizontal irradiance measured by a single sensor and the power output of a single wind turbine, as well as for an averaged solar sensor field and an aggregated wind farm. Moreover, the dependency of the time series' spread on the solar elevation angle, and the wind speed, respectively, is investigated in order to assess the risk of flickering in relation to these variables. The results show that the conditional distribution functions deviate strongly from Gaussian statistics and possess positive skewness, while the risk of flickering events in wind power and solar irradiance generally increases with wind speed and solar elevation, respectively, for single point measurements. Spatial averaging leads to flickering risk reduction.