Building integrated photovoltaic and cool roof passive ventilation strategy in the refurbishment of existing buildings: a Case Study in Italy

The paper reports about an experimental case study in Italy: the energy retrofit of a complex of 10 rural buildings in the Province of Reggio Emilia. The environmental technical solutions have been studied “ad hoc” to improve energy efficiency of buildings, making them suitable for hydroponic and aquaponic greenhouses cultivation. The intervention has involved the removal of the asbestos layer and the installation of a new and more thermal performing roof with integrated photovoltaic modules, for a total Peak Power of 785.4 kWp (744,4 Btu/s). In particular, a new false ceiling has been studied to act as a thermal buffer, aiming at protecting the indoor volumes from external thermal fluctuations and radiation loads, reducing thermal losses in winter nights and mitigating heat gains in summer. The air gap will be used in summer and winter to regulate the internal temperature, ensuring in all seasons indoor optimal climatic conditions. The solution has been found very efficient and cost effective, with the addition of the environmental benefits given by the considerable electricity production allowed thanks to the PV plant.