SPLTRAK Abstract Submission
Measuring Irradiance with Bifacial Reference Panels
Nicholas Riedel-Lyngskær1, Jan Vedde2, Peter B. Poulsen1, Sergiu Spataru1
1Technical University of Denmark, Department of Photonics Engineering, Roskilde, Denmark
/2European Energy A/S, Søborg, Denmark

This paper describes the hardware and results from an outdoor testbed that is designed to assess rear plane-of-array (POA) irradiance measurement approaches. The measurement system contains five optical sensor types, consisting of pyranometers, reference cells, photodiodes, a spectrometer and a bifacial/monofacial reference module pair–all covering various spatial resolutions on the rear POA. The implied uncertainties associated with the different sensor types, at various positions, are assessed with the bifacial performance ratio (PRBIFI) of a 14.2 kWp string of identical bifacial technology as the reference panel. We find that a bifacial/monofacial reference module pair can be used to accurately determine PRBIFI and avoid the complications in rear POA sensor placement.