Combining Solmetric SunEye data with simple 3D modeling to improve residential photovoltaic shade impact predictions

To estimate shade impact to a PV array, standard practice is to measure solar access at the corners of an array and interpolate the shade impact to the modules in between. 3D modeling techniques, however, show that structural shade impact is highly localized. Diffuse light conditions can further reduce the impact of shading. In regions with many overcast days, it is thought that the standard method overestimates the impact of structural shade. In this work, direct solar access measurement is combined with simple 3D modeling, and then compared to the standard method and field performance.