Prediction of Optimum Tilt Angle for Parabolic Trough with the Long Axis in the North-South Direction

A computer model is developed for a parabolic trough oriented north-south to obtain the optimum tilt angle βotp, all over the year as well as for each month at any latitude angle (L). Using least squares method, two empirical formulae were obtained for calculating βopt one for all year around, while the second for each month. A comparison between the proposed incident angle with the well known value for the polar orientation shows an excellent agreement. The present study showed that monthly adjusted parabolic trough reached 99.2% efficiency of that two-axis tracking trough.