Optical Tests on a Curve Fresnel Lens as Secondary Optics for Solar Troughs

Table 1

Concentration factor C as a function of α for lens_A.

α (°)	mm	mm	mm	mm	mm
40	1.56	1.67	1.77	1.84	1.87
35	1.51	1.64	1.74	1.83	1.86
30	1.46	1.58	1.69	1.80	1.84
25	1.45	1.53	1.62	1.74	1.79
20	1.42	1.51	1.59	1.68	1.71
15	1.38	1.46	1.54	1.62	1.65
10	1.36	1.45	1.51	1.56	1.58
5	1.35	1.44	1.49	1.54	1.57
0	1.35	1.44	1.49	1.54	1.56
−5	1.34	1.42	1.48	1.54	1.56
−10	1.36	1.45	1.51	1.57	1.60
−15	1.39	1.47	1.55	1.61	1.65
−20	1.42	1.52	1.59	1.67	1.72
−25	1.46	1.56	1.65	1.74	1.80
−30	1.52	1.63	1.73	1.83	1.87
−35	1.58	1.69	1.81	1.89	1.89
−40	1.65	1.76	1.84	1.90	1.90