Results of the round robin calibration of reference solar cells within the PhotoClass project

Ingo Kröger,Harald Müllejans,David Hinken,Gabi Friesen,Stefan Winter,Tom Betts,Ralph Gottschalg,Lorentz Rimmelspacher,Sebastian Dittmann,Werner Herrmann,Johannes Stang,Karsten Bothe,Diego Pavanello,Dirk Friedrich,Elena Salis,Jimmy Dubard,Martin Bliss,Jochen Hohl-Ebinger

doi:10.1051/ijmqe/2018006

Abstract

An intercomparison of terrestrial photovoltaic (PV) calibrations was performed among a number of European calibration and testing laboratories that participated in the European Metrology Research Program (EMRP) project “PhotoClass”. The purpose of this intercomparison was to evaluate the comparability of calibration and testing services within the stated uncertainties of the individual laboratories. The calibration objects were two world photovoltaic scale (WPVS)-type reference solar cells, one made from crystalline silicon and one made from GaAs. The calibration value (CV) was the short-circuit current under standard test conditions (ISTC). In conclusion, it was found that the CVs are all consistent within the stated uncertainties. This result strengthens the reliance in the calibration chain and in the PV calibration infrastructure in Europe.

Highlights

Traceable calibration and testing of photovoltaic (PV) devices is the very basis of assuring the worldwide comparability of the electrical parameters of PV products such as the efficiency and the nominal power
An intercomparison of terrestrial photovoltaic (PV) calibrations was performed among a number of European calibration and testing laboratories that participated in the European Metrology Research Program (EMRP) project “PhotoClass”
The calibration chain links the industrial production via calibration and testing laboratories to national metrology institutes (NMI) and to the SI units

Summary

Introduction

Traceable calibration and testing of photovoltaic (PV) devices is the very basis of assuring the worldwide comparability of the electrical parameters of PV products such as the efficiency and the nominal power. Every method, every correction procedure and each individual facility lead to different measurement uncertainties, which have to be. Within “PhotoClass” project the participating calibration and testing laboratories upgraded their facilities to perform energy-rating related measurements. The intention of this intercomparison was the final assessment of these facilities in regard to calibration at standard test conditions (STC), to be used as reference point for the energy-rating measurements

Calibration objects

Instrumentation of participating laboratories

Measurement results

Data treatment

Findings

Relative SR