Developing a method and simulation model for evaluating the overall energy performance of a ventilated semi-transparent photovoltaic double-skin facade

A comprehensive simulation model has been developed in this paper to simulate the overall energy performance of an amorphous silicon (a-Si) based photovoltaic double-skin facade (PV-DSF). The methodology and the model simulation procedure are presented in detail. To simulate the overall energy performance, the airflow network model, daylighting model, and the Sandia Array Performance Model in the EnergyPlus software were adopted to simultaneously simulate the thermal, daylighting, and dynamic power output performances of the PV-DSF. The interaction effects between thermal, daylighting, and the power output performances of the PV-DSF were reasonably well modeled by coupling the energy generation, heat-transfer, and optical models. Simulation results were compared with measured data from an outdoor test facility in Hong Kong in which the PV-DSF performance was measured. The model validation work showed that most of the simulated results agreed very well with the measured data except for a modest overestimation of heat gains in the afternoons. In particular, the root-mean-square error between the simulated monthly AC energy output and the measured quantity was only 2.47%. The validation results indicate that the simulation model developed in this study can accurately simulate the overall energy performance of the semi-transparent PV-DSF. This model can, therefore, be an effective tool for carrying out optimum design and sensitivity analyses for PV-DSFs in different climate zones. The methodology developed in this paper also provides a useful reference and starting point for the modeling of other kinds of semi-transparent thin-film PV windows or facades.