solar energy potential from photovoltaic systems in the urban context. Solar power as a source of low carbon energy is an essential component for the sustainability of cities and its implementation and management, through urban planning practices, can play a strategic role in improving the energy efficiency of cities. Within this framework, the amount of energy provided by the integration of photovoltaic systems into existing buildings and their energy consumption, are two key indicators to identify the neighborhoods of the city that behave as urban units with positive, negative or balanced energy performances. On this basis, a workflow that combines geographical information system (ArcGIS®), parametric modeling (Rhinoceros® – GrasshopperTM) and solar dynamic analysis (Geco® – Ecotect®), has been developed. A case study has been conducted in a medium-size city in Portugal: Oeiras. The research also evaluated the implementation of a smart grid model supported in the relationship between urban densities and mixed land-use. This infrastructure provides the connection between the cellular units and the city energy system in order to optimize the demand-supply balance. In this way, the results reveal how widespread integration of PV systems, in the long term, can give rise to cities with better energy performances and thus contribute to mitigate greenhouse gas (GHG) emissions related to fossil fuels consumption.