From solar constraints to urban design opportunities: Optimization of built form typologies in a Brazilian tropical city

Faced with current energy constraints of fast-growing cities in developing countries, urban morphology has been pointed out as a pivotal issue on shifting to climate adapted urban environments. In this context, this paper addresses the twofold sustainable energy challenge of tropical cities: the major potential in harnessing solar energy as renewable resource for local electricity production and the energy demand due to the undesirable solar heat gains in buildings. The methodological approach chosen consists of identifying, assessing and adapting existing urban typologies to these conflicting strategies. Through a case study for the Brazilian city of Maceió, five urban typical configurations are identified using a set of energy-related morphological parameters. They are assessed regarding their envelope solar potential for energy production, daylight availability and potential solar gains. The parameters are then examined through a Design of Experiments for sensitivity analysis followed by a multi-objective optimization of the most relevant design factors, aiming at maximizing solar potential for energy production and minimizing potential solar gains, while keeping appropriate indoor daylight levels. Building regulation and daylight thresholds are considered as design constraints. Results indicate significant improvements while the spreading of solutions on the design space revealed a large number of potentialities.