Use of photovoltaic modules as static solar shadings: Retrofit of a paleontological site in Rome.

An innovative approach for the design of a Building Integrated PhotoVoltaic system (BIPV) is tested in a prefabricated building with a glass facade on the southern side. The aim is to reduce the occurrences of excess heat in Summer using photovoltaic (PV) system as static shadings. Standard “off the shelf” photovoltaic modules set along the southern facade are used for the static shadings. The optimization involves the tilt angle and the distance of the PV arrays in a parametric design environment and aims at reaching the Combination Optimized to Meet Building Objectives (COMBO). The effect of PV shading on indoor microclimate and energy consumption of the building was evaluated by means of whole building dynamic simulation. The proposed design, as a passive control of indoor climate, achieves a decrease of 0.4°C in the yearly mean temperature and a reduction of 0.5°C of the maximum daily fluctuation with respect to the geometry without it. As for the energy consumption (active control), there is a reduction of 27.6% in the cooling hours even if the total energy over the period increases of about 1.18 kWh/m2. The methodology features two main innovations which improve speed and versatility in the definition of a potential refurbishment by means of the dual approach given by the whole-building dynamic simulation and the BIPV system.