Auto-calibration method for high concentration sun trackers

•Systematic method to calibrate the pose of different elements of a sun tracker.•Estimation of orientation errors of foundation, HCPV modules and optical sensor.•Increase of the energy performance of around 30% over a regular manual calibration.•Performance increase around 5–7% when calibrating the pose of the solar modules.•Reduction of start-up time and installation costs in large solar plants. High concentration photovoltaic modules allow a significant increase in the electric power produced per unit area. Nevertheless, in order to reach the maximum possible increase in performance, the sun tracker must meet severe specifications regarding sun-pointing accuracy, because the lens-cell sets of the solar modules only work in a very small angle. For the sun tracker to meet these requirements, a precise procedure of installation is necessary in order to minimize errors from different sources such as misalignment of the structure with respect to geographical North, misalignment of the solar modules with respect to the wing of the sun tracker and other structural tolerances. This paper presents an auto-calibration algorithm which allows to work with higher tolerances in the installation process by estimating some sources of error instead of spending installation time trying to minimize them. Simulation and experimental results with a testing sun tracker are exposed showing the benefits of the proposed method with respect to a manual calibration in terms of power performance.