Evaluating Vertical Building Integrated Photovoltaics With Standard Performance Metrics

Net-zero legislations are being implemented around the world to reduce buildings’ carbon emissions. Various new building technologies are developed to meet these new requirements. Building integrated photovoltaics (BIPV) is one of these technologies, being used to harvest solar energy on-site. However, they lack standard and user-friendly metrics to evaluate their overall performance. This paper investigates several standard metrics and proposes new ones for assessing the performance of vertical BIPV. The seasonal and annual energy production ratio are newly proposed metrics to compare the energy output of vertical BIPV to a south-facing PV system at optimal tilt and same geographical location. The annual specific yield and performance ratio, two standard metrics in solar industry, are also being presented to evaluate the system’s capability with respect to standard testing conditions. Finally, a payback period scaling factor is investigated as a method for rapid assessment of payback period for vertical BIPV systems. These metrics are reported for six distinct regions spanning across the US. With such metrics, vertical BIPV performance potential and the cost of implementing them at various locations in the US is more easily understood, which may increase the demand and acceptance of this type of technology.