For the purpose of designing the high efficient static solar concentrator on automobile, we discuss the way to increase the aperture area. The 2-dimensional (2D) single and double refraction models based on the Snell's law are prepared under the conditions of random azimuth and large off-angle of the incident ray. We find that the center height of the lens is a key parameter to increase the aperture size. For lens array systems, the optimum center height is determined by the upper limit which is required to suppress the shadowing loss at the adjacent lenses. We demonstrate the ray tracing of the 2D lens model.