The benefit of a dense network of all-sky imagers for regional satellite-based short-term forecasts of solar irradiance

Abstract

DLR operates the Eye2Sky measurement network around Oldenburg. This network is designed to provide short-term forecasts of solar irradiance. For this, it is equipped with All Sky imagers and irradiance sensors. On the other hand, intraday-forecasting of solar irradiance is operationally done with satellite-based methods. In this context we have developed a method to optimize the combination of a satellite-based forecast (using the MSG satellite and the Heliosat3 method) with the ASI network-based forecast (using the Eye2Sky ASI network). These forecasts have very different spatio-temporal resolutions, thus inherently different forecast horizons. In this study we want to assess in which contexts this combined forecast presents advantages with respect the individual forecast in terms of statistical uncertainty.