To perform this comparison, the compound parabolic concentrator with a restricted exit angle of 65 (CPC-65) and the one without exit angle restriction (CPC-90) were fabricated and tested for concentrating radiation on multi-crystalline solar cells. Both CPC-65 and CPC-90 are identical in the acceptance half-angle (20 degrees) and geometrical concentration factor (2x). Theoretical calculations showed that CPC-90 based PV system (CPV-90) annually concentrated about 3-5% more radiation on solar cells as compared to CPC-65 based PV system (CPV-65). For CPV-65, all radiation would arrive on the solar cells at the incidence angle less than 65 degrees, but for CPV-90, about 8-10% of annual collectible radiation would arrive on solar cells at the incidence angle larger than 65. Measurements at outdoor conditions showed that the CPV-65 performed slightly better than CPV-90 in terms of short-circuit current and power output as the projection incidence angle of solar rays on the cross-section of CPC-troughs (theta(p)) less than the acceptance half-angle, otherwise the CPV-90 did better. Compared to CPV-90, the power output at maximum power points from CPV-65 were slightly higher, and increases of 2.1%, 5.4% and 8.17% were measured for theta(p)=0 degrees, 10 degrees and 16 degrees, respectively. Analysis indicated that effect of solar flux distribution over solar cells on power output of both CPVs was almost identical and insignificant, and the CPV-65 performed slightly but insignificantly better than the CPV-90 in terms of annual power output except in areas with poor solar resources where the annual power output from both systems was almost identical. (C) 2015 Elsevier Ltd. All rights reserved.