Renewable and sustainable energy generation technologies have been in the forefront due to concerns related to environment, energy independence, and high fossil fuel costs. As part of the EU’s 2020 targets, it is aimed to reach a 20% share of renewable energy sources in final energy consumption by 2020, according to EU’s renewable energy directive. Within this context national renewable energy targets were set for each EU country ranging between 10% (for Malta) and 49% (for Sweden). A large share of renewable energy research has been devoted to photovoltaic systems which harness the solar energy to generate electrical power. As an application of the PV technology, building integrated photovoltaic (BIPV) systems have attracted an increasing interest in the past decade, and have been shown as a feasible renewable power generation technology to help buildings partially meet their load. In addition to BIPV, building integrated photovoltaic/thermal systems (BIPV/T) provide a very good potential for integration into the building to supply both electrical and thermal loads. In this study, we comprehensively reviewed the BIPV and BIPVT applications in terms of energy generation amount, nominal power, efficiency, type and performance assessment approaches. The two fundamental research areas in the BIPV and BIPVT systems are observed to be i) improvements on system efficiency by ventilation, hence obtaining a higher yield with lowering the panel temperature ii) new thin film technologies that are well suited for building integration. Several approaches to achieve these objectives are reported in the literature as presented in this paper. It is expected that this comprehensive review will be beneficial to researchers and practitioners involved or interested in the design, analysis, simulation, and performance evaluation, financial development and incentives, new methods and trends of BIPV systems