Title:	Mining Field I-V and Weather Data for PV Module EQE and Suns-Voc
Author(s):	J.L. Braid, M. Wang, J.S. Stein
Topic:	Photovoltaic Modules and BoS Components
Subtopic:	PV Module Design, Manufacture, Performance and Reliability
Event:	37th European Photovoltaic Solar Energy Conference and Exhibition
Session:	4CO.4.4
ISBN:	3-936338-73-6
Price:	0,00 EUR
Document(s):	presentation

Abstract/Summary:

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This work aims to improve utilization of field I-V and weather data, typically evaluated only with time-series analysis and modeling of basic I-V parameters, to build additional module-level characterization without additional measurements. Here we present two data mining approaches to build module external quantum efficiency (EQE) and Suns-V OC from time-series data. Calculation of module EQE from outdoor data relies on naturally occurring relative intensity shifts in the solar spectrum 1 , as shown in Figure 1. From simultaneous measurements of the solar spectrum and module short circuit current, we compute the effective module EQE via least-squares inversion. An example of our preliminary EQE result is given in Figure 2. Module Suns-Voc from outdoor data, which we have demonstrated previously 2,3 , uses the naturally varying total incident irradiance to obtain I SC -V OC pairs and construct a pseudo I-V curve 4 (Figure 3). By comparing the pseudo and real I-V curves, module properties such as current mismatch and series resistance can be accurately quantified.