Experimental solar sensor development for photovoltaic two-axis tracking systems

In order to maximize the energy collected by a given Photovoltaic System (PVS), it is worth tracking the position of the sun in such a way to expose the PV panels to the maximum global radiation at any given time. In this context, it is useful to determine the direction of the maximum global radiation, that does not correspond with the condition of orthogonality of the PV surface with the beam component of solar radiation. On this regard it is interesting to investigate a low-cost solar radiation sensing system that reveals this direction. The proposed system consists of a structure of nine photodiodes: a suitable analysis of the output signals reveals the angles of azimuth and solar height, related to the direction of maximum solar irradiance, This paper refers to the development of hardware and software of the prototype system called SoliSector. Outdoor experimental results regarding testing and calibration of the proposed system are also reported.