In situ contactless thermal characterisation and imaging of encapsulated photovoltaic devices using phosphor thermometry. (11th June 2019)

• Record Type: Journal Article
• Authors: Cao, Yameng; Koutsourakis, George; Sutton, Gavin J. M.; Kneller, James W. E.; Wood, Sebastian; Blakesley, James C.; Castro, Fernando A.
• Is Part Of: Progress in photovoltaics. Volume 27:Number 8(2019)
• Page Start: 673
• Page End: 681
• Publication Date: 2019-06-11
• Subjects: contactless -- encapsulation -- in situ -- phosphor -- shunt -- temperature -- thermometry; Solar cells -- Periodicals; Photovoltaic cells -- Periodicals; Solar power plants -- Periodicals; 621.31245
• DOI: 10.1002/pip.3142
• Languages: English
• ISSNs: 1062-7995

Abstract

Abstract: Accurate temperature measurements of a photovoltaic (PV) device are not always straightforward. Compromises between accuracy and spatial resolution often have to be made to give either quantitative single point measurements or qualitative spatial measurements. Phosphor thermometry is demonstrated in this work to measure the temperature of an encapsulated silicon photovoltaic device with uncertainty less than 1 °C. Comparisons with contact thermocouple probes are made under external white‐light illumination and internal resistive heating. Under similar conditions, phosphor thermal imaging shows less sensitivity to sources of uncertainty such as poor probe positioning and reduced thermal contact, allowing the detection of faults and shunt induced thermal hot spots in encapsulated PV devices with a higher degree of confidence. Abstract : In situ characterisation of the temperature inside of an encapsulated photovoltaic (PV) cell using contactless phosphor imaging is demonstrated for the first time, with uncertainty less than 1°C. Embedded phosphor coatings inside encapsulations are sensitive to fast‐occuring temperature changes, such as those originating from shunts in PV devices. This approach is independent of emissivity and works well through glass encapsulation, allowing the detection of faults and shunt induced thermal hot spots in encapsulated PV devices with more confidence.