Design process for optimization of buildings façades for solar irradiation in the Brazilian context

Abstract

This paper shows the development of a process for solar potential optimization for non residential buildings in a high density urban area in the Brazilian context. Photovoltaic systems are generally installed on roof tops of buildings located in low density areas due to the availability of horizontal surfaces, but the developments of cities with tall buildings have encouraged photovoltaic integration on facades. A parametric solar design optimization is proposed, with the aid of the Rhinoceros 5.0 modelling tool, the plug-ins Grasshopper and Galapagos, which enable geometric transformations and optimized results and solar dynamic plug-in (DIVA for Rhino) for solar radiation analysis. The optimization criterion is based on the economic viability of the installation, through a minimum level of solar radiation that allows the investment return. The approach aims to maximize the solar access of a new building in existing urban area in Florianopolis – SC/Brazil, in the central area of the city. In this area, a reference building is chosen to analyze the influence of urban context on the solar radiation availability. From a reference shape, modelled in accordance with the occupancy limits from current Master Plan, different combinations of parametric transformations were tested: Twist, Slope, Rotation and Taper. The optimization process resulted in a larger area of the envelope with radiation levels above the fitness value.Through this process it was possible to identify the optimized building shape for solar radiation and to verify if facades can be exploited for energy production in dense urban areas in the Brazilian context. Due to the large energy concerns in Brazil and the great potential of using solar energy due to high solar radiation levels, studies that enhance the use of alternative renewable energy are fundamental to the dissemination of this potential.