pv magazine test is designed to help investors in their module purchasing process, while at the same time allowing manufacturers to spot problems and improve their production practices. The measurements are carried out in GSolar’s test laboratory in Xi’an, China. To ensure the quality of Gsolar’s tests, pv magazine chose CEA as a partner. It acts as an independent third-party expert, and monitors all steps of the testing program to ensure measurement protocols are respected.
|Product#||Test date||Manufacturers||Product||Type||Name plate power (W)||Visual Grade||EL Grade||Low Irradiance Grade||Pmax temperature coefficient Grade||PID Loss Grade||Average||Sample selection method||LID Grade||LeTID Grade|
|41||23/10/2022||Tongwei||TH545 PMB6 58SDC||PERC||545||100||100||77||86||86||87||1||83||98|
|42||16/5/2023||DAS Solar||DH144NA-570||Bifacial TOPcon||570||100||100||67||99||85||87||3||/||-|
|45||19/06/2023||Trina||TSM-NEG9RC.27 xxxW||Bifacial TOPcon||425||100||100||65||96||96||89||3||/||-|
Modules are given a grade from 0 to 100 points for each test. In calculating the average grade of the module, each individual test grade is given a certain weighting as shown in the table. The tests “Visual inspection” and “EL image inspection” each get a 10% weighting, while the tests “Low irradiance efficiency loss” and “Pmax temperature coefficient” each receive a 25% weighting. Given the importance of PID resistance, the test for “PID loss” receives the highest weighting, namely 30%.
Sample method categorization: 1. sample randomly selected by CEA from a large production lot. 2. Sample purchased from the market by CEA 3. Sample provided by supplier, without random selection
The following two articles explain the relevance of each test procedure. Please be aware, that we have changed the test grading system after publication, from a letter-based system to a numeric system (0 to 100). Accordingly, the following two articles in the September 2017 issue of pv magazine (global edition) still use the original letter-based system. In 2021 the test installation was upgraded to accomodate large format modules, and at the start of 2022 the test protocol was updated to include comprehensive testing for light elevated temperature induced degradation (LETID).
Introduction to LETID testing
LETID (light and elevated temperature-induced degradation) is a mode of degradation of crystalline silicon PV cells that was identified and researched a few years ago. The initial research was spearheaded by Q Cells, which also coined the term LETID in 2015, with Australia’s University of New South Wales contributing important work on the root causes and mechanism.
Big modules, new beginnings
Earlier this year, the pv magazine test outdoor array in Xi’an, China underwent extensive modifications so it could accommodate the form factors and electrical characteristics of new modules based on larger wafer formats. George Touloupas, senior director of technology and quality at CEA, takes us through the new system and the reasons why the modifications were needed, as well as the role of newly installed microinverters supplied by AP systems.
The new module test
Module reliability: pv magazine’s new module test is kicking off. The first candidate is Jolywood with its bifacial n-Pert module. The test is designed to help investors in their module purchasing process, while at the same time allowing manufacturers to spot problems and improve their production processes.
Method for the modules
Testing methodology: George Touloupas, Director of Technology and Quality at CEA, gives a detailed account of the methodology behind pv magazine test, and explains the results from the first round of testing.
Read all related magazine articles here.
This page was last updated on July 14, 2023.