Characteristic Declination—A Useful Concept for Accelerating 3D Solar Potential Calculations

The characteristic declination is the for day on which daily extraterrestrial irradiation a horizontal surface identical to its monthly average value. It was introduced as means determine values of irradiation. Herein, potential usefulness reduce computing time when mapping solar in complex urban areas explored. This simplification reduces demand by factor 30× while introducing +5% +8% error annual typical neighborhood low and midlatitudes. Errors are larger (+10% +12%) high latitudes. magnitude errors comparable other relevant uncertainties tools, associated with radiation modeling, layout details buildings, or photovoltaic (PV) energy yield models.