This paper describes the experience of teaching power systems basics to undergraduate engineering students using a pedagogical approach that is based upon computer-mediated and problem-based learning in an integrated way. In this approach, an interactive learning environment based on web technologies replaces the traditional lectures. The pedagogical project behind this approach is focused on the problem-based learning paradigm, where the students are instigated to construct the knowledge required to solve the problem (constructivist learning). The paper addresses the technological aspects, such as how to create simulators using Java applets and animation, as well as the pedagogical aspects, such as student performance and knowledge acquisition. The experience of using this approach at the State University of Campinas, Brazil, during the years 2001/2002 is described in detail. Advantages and disadvantages of this approach are also addressed and finally the students point of view are presented based on surveys.