Optimize and Develop of Empirical Correlations Models of Solar Energy on Horizontal and Tilted Surface over Saudi Arabia
Khalil SA
Published on: 2023-01-11
Abstract
Solar radiation data are essential in the design of solar energy conversion devices. In this regard, empirical models were selected to optimize the solar radiation on horizontal and inclined surfaces. The measured data in this article were used during 25 years of solar radiation over Jeddah, Saudi Arabia from 1992-2016 to optimization and developing a new empirical correlations on horizontal and inclined surfaces. The maximum solar radiation occurs in summer and spring months, while the minimum solar radiation occurs in winter months. The solar irradiance measurements strongly affected by cloud. Surface estimations of the diffuse segment of sun powered irradiance are especially touchy to overcast cover. Starting from cloudy days in the morning, the dark clouds gradually dissipate throughout the afternoon to the evening, until the dark clouds are completely cleared. The statistical indicators of main base error MBE, root mean square error RMSE, mean percentage error MPE and t-state are done. The values of correlation coefficients (R2) are higher than 0.98 and the values of the RMSE are found the range 1.95– 4.65. The both (Rb) and (Rt) decrease with increasing tilted angle (β) during the summer months, while during winter months, (Rb) and (Rt) are increase with increasing (β) until an optimum value beyond which the behavior is reversed. The high tilt is required to meet the energy demand in the winter months when the insolation on a horizontal surface is usually low. The results revealed that the (β) varies with the month of the year. The revealed results indicate that the daily (β) varies from 58.5° in January to 0.5° in May months, but the values of (β) were negative for the period from May to August months. Isotropic, Perez, Hay, and Klucher models, so anisotropic models Hay, Klucher, and Perez models are basically in a predictive state, and generally have similar performance, that is, the irradiance incident on the inclined surface. The observation results of the Perez model and the Klucher model describe the irradiance at tilt more accurately than other models. The results of this study are similar to previous studies [65,66].