This research aims to develop a methodology for the evaluation of the potential energy saving and energy generation of semi-transparent PV windows in Brazilian office buildings. The evaluation is based on computer simulations: a daylighting simulation for the investigation of the available annual daylight with different window systems using Daysim/Radiance program and the simulation of the energetic performance using the program EnergyPlus. The simulations were accomplished for two cities in two different climatic zones of Brazil and compared to a German city. The results show that it is possible to reduce the energy consumption for artificial lighting and air-conditioning using appropriate control systems and furthermore to generate energy using semi-transparent photovoltaic panels in windows. Though only one building geometry was analyzed the results suggest that the potential of this technology is high in Brazil. (C) 2013 Elsevier B.V. All rights reserved.