Analisys of Daylight Availability in Italy Trough Different Louminous Efficacy Models
Abstract
Abstract This paper presents first results of an action aimed at developing an Italian database of Typical Meteorological Year (TMY) for the global and diffuse outdoor illuminance, starting from solar irradiation measurements and luminous efficacy models. The main objective is to provide reliable climatic data to be used for the estimation of the daylight availability in buildings and predict the energy requirements for electric lighting with higher accuracy than the actual relevant standard. ENEA developed the national solar radiation atlas during the past years, implementing dedicated and validated models to predict the global, direct and diffuse irradiation, starting from satellite remote sensing. For this study, the most relevant luminous efficacy models were applied to develop illuminance TMY starting from solar irradiation data for three localities of the Italian territory (Milan, Rome, Palermo). The results provide an initial data-set that will be tested versus land measurements in 2016, to check if the tested models provide reliable results and, eventually, tune the most accurate according to the measured values. The results achieved for the different models are discussed, with a special focus on data management that might be adequately used for lighting in buildings ‘applications. Keywords: Daylight availability;luminous efficacy; outdoor illuminance, TMY