The thermal behavior of an absorber plate in a solar collector is investigated using finite element analysis. The thermal behavior and efficiency of two absorber plate geometries are studied, using a typical solar collector with a rectangular profile as reference, and a proposed absorber plate with curved geometry. An analysis of the most important parameters involved in the design of the absorber plate was carried out, indicating that the curved geometry of the absorber plate yields an average efficiency similar to 25 % higher than the conventional rectangular geometry. The results suggest that a curved profile made of materials such as aluminum with thermal conductivity higher than 200 W/m degrees C, plate thickness of the order of 2-3 mm and with a large density of tubes per unit area of the collector's plate greatly benefits the thermal efficiency of the solar collector.