IEA - Report

Long term satellite hourly, daily and monthly global, beam and diffuse irradiance validation. Interannual variability analysis

IEA Report (pdf)

Abstract

Satellite derived solar radiation is nowadays a good alternative to ground measurements for renewable energy applications. It has the advantage to provide data with a good accuracy, the best time and space granularity, in term of real time series and average year such as TMY.

This report presents results of a long term validation in the European and Mediteranean region of six nowcast satellite products in hourly, daily and monthly values, and six average products on an annual basis. The performance of all the products is put forward with the natural interannual variability; for comparison purpose, the SatelLight model is also included in the results.

The main results are:

• the accuracy of the derived global irradiance reaches 17% with no bias, and 34% for the beam component with a negligible bias,
• even with some high discrepancies for specific sites and models, on the average, all the products provide the annual global irradiation within one standard deviation of the interannual variability, with a bias standard deviation from 2% to 5%.
• eight of the nine models provide beam irradiance within one standard deviation, the best bias standard deviation is 6%.