This paper discusses the performance evaluation of anidolic concentrators in an overcast sky condition. The concentrators were designed, with acceptance angles of 60°, 70° and 80°, first by maintaining the profile of the concentrator’s uniform and secondly by keeping the height uniform. Studies were done using these concentrators with a model light pipe and the performance was compared with that of an acrylic dome and a profiled Fresnel collector. For a given condition, the illuminance ratio (ratio of illuminance measured at the base of the pipe to external illumination) increased with the acceptance angle. For a given acceptance angle, the concentrator with uniform height and variation of entrance aperture, performed better than a concentrator having a uniform profile.