Chapter 12 - Forecasting Solar Irradiance with Numerical Weather Prediction Models

Abstract

Forecasts of solar irradiance with lead times greater than a few hours rely on numerical weather prediction (NWP) models. NWP is indispensable, but also complex and prone to error. This chapter aims to provide users of solar-irradiance forecasts with an appreciation of the character and magnitude of some errors in state-of-the-art NWP models. The chapter summarizes model structure, with emphasis on irradiance aspects. It then outlines the configuration of several commonly used operational NWP models. Finally, the chapter discusses irradiance-related model errors and speculates on their cause.