Renewable energy sources are one of the main topics not only in scientific researches but also in daily life. In this study, it is aimed to investigate Turkish primary and secondary students' knowledge about the renewable energy sources. 107 primary and secondary school students participated in the study. Open-ended questions are used to determine students' knowledge about the topic. Students' answers were analyzed using descriptive analysis technique. It is revealed that there were major differences in students' answers according to grades. In addition, these answers were depended on their conceptual frameworks. These frameworks can be classified into two categories as daily life and school context. It is hoped that this study would contribute both to understand students' knowledge related to this topic and to teach energy sources based on contextual approaches. (C) 2010 Elsevier Ltd. All rights reserved.