Azimuth Detection from Solar Irradiance on Tilted Surfaces
Abstract
Azimuth misalignment with respect to nominal values is a frequent source of uncertainty when working with tilted plane solar measurements. Two complementary methods to estimate the true azimuth of a tilted surface using global irradiance measurement series are discussed and implemented. Ground data from an arrangement of tilted pyranometers with different azimuths, along with GHI, DNI and DHI data, are used to validate the methods. By averaging and combining both methods we obtain an estimated azimuth for each surface orientation and an estimation of its uncertainty. The results show good agreement with nominal azimuth values, with uncertainties that increase when the surfaces move away from the zero azimuth and from the horizontal plane.