GB/Z 46984.4-2026Photovoltaic cells - Part 4: Measurement of light and elevated temperature induced degradation of crystalline silicon photovoltaic cells (English PDF)

Foreword

This document is a standard or guiding technical document.

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents". Drafting.

This document is Part 4 of GB/T (Z)46984 "Photovoltaic Cells". GB/T (Z)46984 has already published the following parts.

---Part 1: Test Methods for Light-Induced Degradation of Crystalline Silicon Photovoltaic Cells;

---Part 2: Electroluminescence images of crystalline silicon photovoltaic cells;

---Part 3: Measurement of Current-Voltage Characteristics of Bifacial Photovoltaic Cells;

---Part 4: Test methods for photothermal induced degradation of crystalline silicon photovoltaic cells.

This document is equivalent to IEC TS63202-4:2022 "Photovoltaic cells - Part 4: Test method for photothermal degradation of crystalline silicon photovoltaic cells".

The document type has been changed from IEC technical specifications to my country's national standardization guidance technical documents.

The following minimal editorial changes have been made to this document.

---The scope has been changed; the content described in the scope of IEC TS63202-4:2022 has been moved to the introduction.

---The clause numbers in Chapter 6 have been changed from a)~j) to 6.1~6.10.

Introduction

GB/T (Z)46984 proposes test methods for photovoltaic cells, which have positive guiding significance for the testing of photovoltaic cells. GB/T (Z)46984 is proposed to consist of the following parts.

---Part 1: Test Methods for Light-Induced Degradation of Crystalline Silicon Photovoltaic Cells, the purpose of which is to specify the test methods for light-induced degradation of photovoltaic cells.

---Part 2: Electroluminescence Images of Crystalline Silicon Photovoltaic Cells, the purpose of which is to specify the methods for acquiring the EL of photovoltaic cells and various optical methods. Description of defects in volt-ampere (EL) images.

---Part 3: Measurement of Current-Voltage Characteristics of Bifacial Photovoltaic Cells, the purpose of which is to specify the measurement method for IV of bifacial photovoltaic cells.

---Part 4: Test Methods for Photothermal Induced Degradation of Crystalline Silicon Photovoltaic Cells. The purpose is to specify the power degradation of photovoltaic cells under photothermal induction. Subtraction test method;

---Part 6: Water Bath Testing Method for Crystalline Silicon Photovoltaic Cells. The purpose is to evaluate the performance of crystalline silicon photovoltaic cell pastes under high temperature and high humidity conditions.

Whether the lining has fallen off, and the extent of the falloff;

---Part 7: Test Methods for Bending Strength of Crystalline Silicon Photovoltaic Cells. The purpose is to evaluate the bending strength of crystalline silicon photovoltaic cells and reduce... Risk of cell breakage;

---Part 8: Test Methods for UV-Induced Degradation of Crystalline Silicon Photovoltaic Cells. The purpose is to evaluate the UV resistance of crystalline silicon photovoltaic cells. Capabilities that reduce encapsulation losses at the component level.

GB/T 46984.1 specifies the initial light-induced degradation (LID) test method for crystalline silicon photovoltaic cells. This method can be used to evaluate the cell's performance in the light-induced degradation stage.

The study outlines the risk of LID (Low Irradiation Discharge) at moderate temperatures and for short irradiation periods, and specifies that the test should be terminated when the cumulative irradiance reaches 20 kWh·m^-².

The power generation of photovoltaic modules is affected by the inherent photothermal induced degradation performance of the cells used. Photothermal induced degradation includes LID (Liquidity Ingress) and its components.

Its degradation mechanism. The experimental methods described in this document are used to evaluate the degradation behavior of batteries under high temperature and longer light exposure. By comparison The difference between the maximum output power Pmax under standard test conditions (STC) and the initial Pmax after different cumulative irradiation doses can determine the decay rate.

Rate, maximum attenuation ratio, and possible recovery. Furthermore, this document recommends a curve for describing Pmax attenuation relative to cumulative irradiance.

This helps battery manufacturers determine whether a battery is susceptible to photothermal-induced degradation.

The test method described in this document can measure the overall degradation of the battery under high temperature and light exposure, which is different from some other methods that use boron and oxygen to cause degradation.

LID differs from standards that separate photothermal induced decay from those that limit decay to carrier injection-induced decay. The overall decay measured using the method described in this document is different.

It has a stronger correlation with attenuation under actual outdoor application conditions and can better assess the risk of photothermal induced attenuation. For approximately Batteries exhibiting strong initial degradation within 20 kWh·m^-² can be tested using the methods described in GB/T 46984.1. Additionally, they conform to GB /Z 119.

Compared to the photothermal induced degradation test method described in the previous paper, this method uses the same temperature but selects open-circuit conditions for the battery. Use a higher injection volume to shorten the test time.

The test methods described in this document can be used to detect the risk of photothermal-induced degradation in batteries and to determine measures to improve photothermal-induced degradation.

Effectiveness (e.g., for rapid testing and monitoring during battery production), thereby helping to increase the power generation of photovoltaic modules.

1 Scope

This document specifies the test method for photothermal induced degradation of crystalline silicon photovoltaic cells, including terms and definitions, test equipment, sample preparation, and practical procedures. Test methods and reports.

This document applies to crystalline silicon photovoltaic cells (hereinafter referred to as cells).

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies. This document.

Note: GB/T 6495.1-2025 Photovoltaic devices - Part 1: Measurement of photovoltaic current-voltage characteristics (IEC 60904-1:2020, IDT)

Note: GB/T 6495.2-2025 Photovoltaic devices - Part 2: Requirements for standard photovoltaic devices (IEC 60904-2:2023, IDT)

Note: GB/T 6495.9-2025 Photovoltaic devices - Part 9: Characteristic classification of solar simulators (IEC 60904-9:2020, IDT) andsymbols)

Note: GB/T 2297-2025 Terminology for Solar Photovoltaic Energy Systems (IEC TS61836:2016, NEQ)

IEC 63202-1:2019 Photovoltaic cells - Part 1: Test methods for light-induced degradation of crystalline silicon photovoltaic cells

Note: GB/T 46984.1-2025 Photovoltaic cells - Part 1: Test methods for light-induced degradation of crystalline silicon photovoltaic cells (IEC 63202-1:2019, IDT)

IEC TS63202-2:2021 Photovoltaic cells - Part 2: Photoluminescence images of crystalline silicon solar cells

Note: GB /Z 46984.2-2026 Photovoltaic cells - Part 2: Electroluminescent images of crystalline silicon photovoltaic cells (IEC TS63202-2:2021, IDT)

IEC TS63342 Test for photothermal induced degradation (LETID) of crystalline silicon photovoltaic modules [C-Siphotovoltaic]

Note: GB /Z 119-2026 Test for photothermal induced degradation (LETID) of crystalline silicon photovoltaic modules (IEC TS63342:2022, IDT)

3 Terms and Definitions

The terms and definitions defined in IEC TS61836 apply to this document.

The URLs for the terminology databases maintained by ISO and IEC for standardization are as follows. […]