During the last 20 years the research of Building Integrated Photovoltaic Systems (BIPV) related with different techniques and concepts has been widespread, but rather scattered. In BIPV systems photovoltaic panels functioning as an integral part of the building envelope, therefore, enhances the aesthetic appeal of the building. In addition of providing renewable energy, they may also contribute to improving the indoor climate when thermal energy released during the conversion process is withdrawer efficiently, passively or actively recovered (BIPV/T). The increase in BIPV/T research since 1990s, is a consequence of the growing interest of the construction industry in offering new alternatives to traditional approaches. The paper is reporting in the first part, a BIPV classification focused on the building integration aspect and on the characterization of the main parameters involved rather than on technologies used or the performance aspects. In the second part, the paper is focused on reporting the experimental results from a particular application, a case study developed in Portugal, where a thermal storage element, Phase Change Materials (PCM) integrates the BIPV.