A framework for assessing the matching between electricity demand and supply of urban buildings equipped with BIPV

Solar energy is the main energy resource available in nature. The potential to generate renewable energy from the sun represents an issue tackled by many authors in the last years, especially for the assessment of the electricity production from PV panels mounted at the top of roofs. On the other hand, the investigation of PV potential for panels mounted on vertical facades needs further studies due both to the urban geometry and its consequent shading effects that can easily lower irradiances, thus decreasing the expected electricity delivery. The present paper aims at developing an integrated approach able on the one hand to estimate the electricity production potential of BIPV for urban buildings, and on the other hand to estimate their energy needs in an attempt to match the energy supply and demands. This is accomplished by considering actual urban morphologies when calculating irradiance values on building envelopes and their energy demand, taking into account both the direct and indirect components of solar radiation. Results are then plotted to the physical model so that it is easy to visually estimate and quantify the most suitable surfaces for photovoltaic applications. Finally, dynamic energy simulations are run for every building in order to get their hourly energy demand profile and to match it with the predicted PV yield. The method is demonstrated for the buildings of the Yasar University campus of Izmir (Turkey), for which this study revealed that the BIPV system could achieve up to 23% of the electricity demands, which complies with the Renewable Energy Directive to cover at least 20% of the energy needs by means of renewable sources by 2020.