Towards solar urban planning: A new step for better energy performance

The aim of this paper is to explore the concept of Solar Urban Planning with the goal of developing an operative methodology to achieve the best conditions towards Zero Energy Building (ZEB). In the last two centuries there has been a transformation in the form of cities, from being relatively compact to a confused urban sprawl. By 2020, all new buildings constructed in the European Union will have to be "nearly zero energy" in response to the Energy Performance of Building Directive. The ZEB goal is technically achievable but dependents on various conditions of the urban structure. By 2050, the population will grow from 7 to 9 billion, the facts are clear and the time to act is now. The task to provide high solar performances buildings could be attained in a better way if the urban planning process integrates a solar energy approach to both new and existing urban environments. A "new step" that determines the solar potential of an urban area, implements a model connected to the needs of buildings and their capacity to produce energy from solar resource integrating solar analysis with parametric urban design, represents a useful tool to be added into the conception phase of urban planning. The methodology has been applied to a case study in Portugal to plan the correct orientation and form of new buildings to guarantee the optimal efficiency of photovoltaic roof and facade systems and calculate their solar energy production. Considering the importance and the complexity to minimize the use of cooling system and reduce the buildings energy consumption, multiple actions are required. Solar urban design is a "new phase" of sustainable urban planning, a phase that has wide horizons of development and could provide new solutions to the worlds energy problem by reducing its consumption and improves the performance of future buildings. (C) 2012 The Authors. Published by Elsevier Ltd.