Validating nine clear sky radiation models in Australia. (October 2015)

• Record Type: Journal Article
• Authors: Engerer, N.A.; Mills, F.P.
• Is Part Of: Solar energy. Volume 120(2015)
• Page Start: 9
• Page End: 24
• Publication Date: 2015-10
• Subjects: Solar energy -- Radiation -- Clear sky -- Modeling; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2015.06.044
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: We validate 9 beam and global clear sky radiation models. Validation completed using 1 min data for 14 sites in Australia. The models are computed using simplified inputs. We find the Simplified Solis, Esra and REST2 models are best for global radiation. We find the Iqbal-C, Esra and REST2 methods are best for beam radiation. Abstract: There have been many validation studies of clear sky solar radiation models, however, to date, no such analysis has been completed for Australia. Clear sky models are essential for estimating the generation potential of various solar energy technologies, the basic calibration of radiation measuring equipment, quality control of solar radiation datasets, engineering design (e.g. heating and cooling of buildings) and in agricultural and biological sciences (e.g. forestry). All of these areas are of considerable interest to the Australian economy and will benefit from an assessment of clear sky radiation models. With the recent provision of one-minute interval radiation data by the Australian Bureau of Meteorology for 20 sites across Australia, such a study can now be undertaken at a level not previously possible. Using up to ten years of data from each of 14 of these sites, clear sky periods are extracted through an automated detection algorithm. With these clear sky periods identified, nine of the most prominent beam and global clear sky radiation models are assessed using the relative Mean Bias Error, relative Root Mean Square Error and Coefficient of Determination as metrics. Further testing assessed model performance as a function of solar zenith angle and apparent solar time. Results show that for global clear sky simulations, the Solis, Esra and REST2 approaches perform best, while the Iqbal, Esra and REST2 methods are the most proficient clear sky beam models.