Prediction of optimum tilt angle of Flat-plate solar collector in Abia State Nigeria

Abstract

Most solar collectors in Nigeria are mounted without consideration of optimum tilt angle for maximum solar radiation. To address the gap, a flat plate surface solar collector of area 0.15 m2, hinged on horizontal support for quick adjustment of inclination between 0 to 90o was fabricated marked out at 1o intervals on a telescopic leg graduated in degrees. Measurement of the solar radiation at varying degrees of inclination was taken between 12:00 noon and 2.00 pm for 4 days at clear sky hours, within the week of nth day of the year. The measurements were taken for each month of the year at Michael Okpara University of Agriculture, Umudike. Umuahia, Abia State, Nigeria, at each degree of inclination. The result showed that the optimum angle of inclination of a flat plate for maximum collection of solar radiation intensities for January to December were 9.5, 9.1, 3.0, 6.4, 9.9, 11.8, 9.0, 7.3, 3.1, 7.0, 10.2, and 11.8o respectively. The study also revealed that the average angle of inclination at which a flat surface solar collector can be mounted at a fixed position in Umudike is 8.14o. The analysis indicated that solar energy gain of 123,314.79 MJm-2, 39,041.24 MJm-2, and 25,610.84 MJm-2 for horizontal, Latitude angle of location and calculated fixed angle of inclination of the solar collector respectively. Comparison of the measured and calculated optimum values of angle of inclination of a flat plate surface for trapping maximum solar radiation intensity indicated a high correlation ( R2 ) of 0.97.