Stationary CPC solar collectors with symmetric and asymmetric mirrors have been studied and tested. In these collectors the distribution of solar radiation on the absorber surface is not uniform, with areas of low and high intensity, variable and depending on the position of the Sun relative to the collector. This effect can be used to improve the efficiency of the collector if the absorber is flat and divided in several sections, which form the channels of fluid flow. By selecting the channels with the higher radiation density, the working fluid can be heated to higher operating temperatures. Here we present work on the optical analysis and experimental tests on models consisting of four channel absorbers. The results show that efficient operation at temperatures in the range of 100-200 degrees C can be achieved with relatively simple types of concentrating solar collectors.