Light Induced Degradation (LID) Test - Solar PV Module Test

In the world of solar energy, the efficiency and reliability of solar photovoltaic (PV) modules are crucial. One of the key tests performed ...

In the world of solar energy, the efficiency and reliability of solar photovoltaic (PV) modules are crucial. One of the key tests performed on solar PV modules is the Light Induced Degradation (LID) test. This test is designed to assess how the performance of the solar panels degrades over time due to exposure to light. In this article, we will delve into what the LID test is, how it is performed, why it is essential for solar PV modules, and the relevant international standard IEC 61215.

What is the Light Induced Degradation (LID) ?

The power loss that may occur when a photovoltaic module is exposed to sunlight is a common phenomenon known as light-induced degradation (LID). The purpose of LID testing is to detect the power loss that may occur when a photovoltaic module is exposed to sunlight so that developers can detect potential problems in advance, maintain the long-term stability of solar cells, and ensure efficient power generation of their cell modules.

How Does The Light Induced Degradation (LID)  Perform?

In the IEC 61215 standard, the attenuation ratio of the module power before and after the cumulative irradiance of 5kWh is usually tested as the initial light attenuation. According to the current LID test standards of major manufacturers, the basic standards implemented are: LID testing usually uses a halogen lamp with a light intensity of 1000W/m2 and a test time of 60 kWh/m2 of energy, equivalent to 20 days. The test instrument is a standard spectrum solar simulator. 

The LID stabilization test consists of a series of light exposure intervals of equal irradiance doses that are above 5kWh/m2. The module performs at its maximum power point (MPP) during light exposure and a constant temperature is maintained around 50°C. The module is flashed after each interval. Suppose the module power difference in the last three flashes is smaller than the threshold value defined by the standard. In that case, the stabilization is considered complete and the accumulated total irradiance dose required is measured. If not, the steps are repeated and the next interval of light exposure is applied. If the performance loss passes 5% after stabilization then the module failed the standard test.-(sinovoltaics)

Why Was The LID Test Performed on The Solar PV Module?

LID can be primarily witnessed in panels with silicon solar cells particularly in PERC modules. It can result in a devastating loss in the conversion and generation of electricity because of the recombination of active defects during the extra carrier injection by illumination. This testing helps ensure the performance of PV modules in their entire product life cycle. Therefore, evaluating LID is of paramount importance for cost-effectiveness and power conversion. 

LID testing

 LID testing requires professional testing equipment and personnel to ensure the accuracy and reliability of the test. At the same time, the test results may be affected by many factors, such as test conditions, equipment accuracy, test methods, etc., so a comprehensive analysis and evaluation of the test results is required. In addition, the following points should be noted for LID testing:

• Avoid mechanical damage or contamination of photovoltaic modules during testing.
• Pay attention to the temperature and humidity of the photovoltaic modules during testing to ensure the accuracy of the test results.
• The test results should be compared with other test results to determine the actual performance of the PV module.
• Test results should be recorded and analyzed promptly so that developers can identify problems in time and take appropriate measures.

     In short, LID testing is an important means to ensure the long-term stability of solar cells, but it requires professional testing equipment and personnel and needs to pay attention to the influence of multiple factors. Only under the correct test conditions can accurate and reliable test results be obtained to provide a guarantee for the long-term stability of solar cells.

Thank you for reading the articles and blogs on www.omkarmhatre.in. Your feedback means a lot to us, so please feel free to share your thoughts on our posts. We value your opinions and believe that discussion leads to growth.

Follow us on our social media platforms to stay updated with the latest articles, exclusive insights, and behind-the-scenes updates.