Risk Evaluation in Predicting Solar Radiation Transmissivity (SRT) Based on Latitude-Incident Angle Ratio of the Radiation

Abstract

Risk evaluation in predicting solar radiation transmissivity, ϑ (SRT) based on the latitude-incident angle ratio of radiation, Φ/ θ was carried out. A model; ϑ = (Φ/ θ)^0.2 was derived, validated and used for predicting the SRTs. This implies that SRT is approximately equal to the fifth root of the latitude-incident angle ratio. The SRT values were compared with values calculated from the actual results and associated deviations evaluated as risk. The risk evolving from evaluating SRT based on (Φ/θ)^0.2 instead of the widely accepted experimental method was < 8 %. The evaluated risk translated into over 92% operational confidence for the derived model as well as over 0.92 reliability coefficients for predicting SRT based on the latitude-incident angle ratio of radiation. Comparative analysis of predicted and actual results show very close alignment of curves of SRT, which precisely translated into significantly similar trend of data points distribution. The standard errors incurred in evaluating SRT from actual and predicted results were all ˂ 0.2%. The correlations between SRT and Φ and θ as obtained from actual and predicted results were all ˃ 0.93.