A Novel Method of Monitoring Global Normal Irradiance With a Stationary Sensor

This paper describes a new method of monitoring the global normal irradiance (GNI) with a completely stationary sensor. A stationary sensor comprises five individual monocrystalline Si cells mounted tangentially along a hemispherical aluminium structure. A prototype stationary GNI sensor has been constructed and a series of outdoor tests were performed. The preliminary results from several test runs show that the concept is completely feasible, and an accuracy of the GNI measurement can be within 1% of the true GNI. This sensor is particularly useful for PV test centers and demonstration plants with different PV array orientations, as well as meteorological stations without sun trackers.