• Dr. K. Rama Gopal
• C. Manjunatha
• S. Pavankumari
• G. Balakrishnaiah
• B. Elijabetthamma, T. Chakradhar Rao, T. Lokeswara Reddy

In the present study, the estimation of diffuse fraction based on clearness index (kt) and relative sunshine (S/S0) over Anantapur region (14.62ºN, 77.65º E and 331m asl) during January 2016 to September 2017 was calculated. The clearness index and relative sunshine was high in the month of February 2017 (0.84±0.01 and 0.64±0.01) and low in the month of June 2016 (0.65±0.09 and 0.51±0.07). The regression analysis was employed to correlate the diffuse fraction with clearness index and relative sunshine. Four models are proposed to estimate the diffuse fraction; Page model, Liu and Jordan model, Iqbal model and Gopinathan model. These proposed models are compared with the well-established models from literature. The statistical analysis were observed between proposed and literature model values of diffuse fraction such as such as mean bias error (MBE), mean percentage error (MPE), root mean square error (RMS), coefficient of correlation (R), coefficient of determination (R2), in this Liu and Jordan model has minimum values of MBE, MPE and RMSE. This indicates that this model is good model for all proposed models having coefficient of determination R2=0.98.

Diffuse fraction, clearness index, relative sunshine

"ESTIMATION OF DIFFUSE FRACTION OF GLOBAL SOLAR RADIATION OVER A SEMI-ARID REGION, ANANTAPUR, A.P.", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 4, page no.251-263, April-2019, Available :http://www.jetir.org/papers/JETIR1904M39.pdf

"ESTIMATION OF DIFFUSE FRACTION OF GLOBAL SOLAR RADIATION OVER A SEMI-ARID REGION, ANANTAPUR, A.P.", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 4, page no. pp251-263, April-2019, Available at : http://www.jetir.org/papers/JETIR1904M39.pdf