Multi-Pyranometer Array Design and Performance Summary

The use of a multi-pyranometer array (MPA) for measuring the solar resouce is an alternative to using thermopile instruments and their associated trackers and shading disks or shadowbands. The MPA consists of three or four pyranometers with fixed orientations and with different views of the sun and sky. By measuring the solar radiation received by each pyranometer and the use of an iterativemodel, direct normal and diffuse horizontal radiation can be determined. Although not as accurate as measuring these quantities directly, the MPA provides a lower-cost approach to measuring solar radiation, and it has excellent reliability due to its simplicity and minimal maintenance requirements. The MPA has no moving parts and does not require periodic adjustments.