The aim of this study is to assess the technical feasibility of solar water heaters (SWH) under Moroccan conditions. Annual simulations in six different regions for two technologies: flat plate and evacuated tube collectors were carried out using TRANSOL program. It is found that high values of solar fraction can be reached in almost the studied regions with the preference of using evacuated tube collectors. Furthermore, the study emphasizes that the location and the climate are determinant parameters on the overall performance of solar water heating systems. (C) 2014 Elsevier Ltd. All rights reserved.