Jul 2023

The LETID Loss in Solar Modules

(Authored by Jaykumar Dhola, Technical Services Manager, STS )

Shedding Light on LETID Loss in Solar Modules

Solar modules have become increasingly popular as a reliable and sustainable source of energy. However, like any technology, they face challenges that affect their performance over time. One significant issue that solar module manufacturers and researchers have been addressing is Light and Elevated Temperature Induced Degradation (LETID) loss. Let’s delve into this phenomenon and its implications for the solar industry.

Understanding LETID Loss:

LETID loss refers to the degradation in solar modules when exposed to a combination of light and elevated temperatures. This degradation leads to a reduction in the module’s power output over its operational lifetime. Key factors associated with LETID loss include:

1. Light Soaking: Light soaking is the exposure of solar modules to sunlight under normal operating conditions. Over time, this continuous exposure to light leads to the degradation of the module’s performance.

2. Elevated Temperatures: High operating temperatures, especially in warm climates or when modules are subjected to high heat, accelerate the degradation process. Elevated temperatures can exacerbate the impact of light soaking and lead to accelerated LETID loss.

3. Boron-Oxygen Complex: The boron-oxygen complex, a defect in the silicon material used in solar cells, plays a crucial role in LETID loss. Under light and elevated temperature conditions, this complex interacts with the silicon lattice, causing performance degradation.

Research and Mitigation Strategies:
Extensive research and development efforts are underway extensivete LETID loss and enhance the long-term performance of solar modules. Researchers are exploring various strategies, including:

1. Material Optimization: Scientists are working on improving the quality of silicon materials used in solar cells to minimize the formation of the boron-oxygen complex. By reducing or eliminating this defect, they aim to mitigate LETID loss.

2. Passivation Techniques: Passivation techniques involve the application of specific coatings or layers on the solar cell surface to minimize defects and enhance the cell’s stability. Passivation layers help reduce the impact of LETID loss and improve module performance.

3. Accelerated Testing: Manufacturers conduct accelerated testing in controlled laboratory environments to simulate long-term exposure to light and elevated temperatures. This testing helps identify potential degradation mechanisms and develop mitigation strategies.

Advancing Solar Module Reliability:

LETID loss is a challenge that the solar industry is actively addressing to improve module reliability and performance. By understanding the underlying mechanisms and implementing mitigation strategies, the industry aims to achieve the following spann: Minimizing LETID loss can extend the operational lifespan of solar modules, ensuring they maintain optimal performance over an extended period.

Higher Energy Yield: Mitigating LETID loss helps preserve the module’s power output, resulting in higher energy yields throughout its lifetime. This maximizes the return on investment for solar installations.

Improved Bankability: Reliable and durable solar modules are crucial for project financiers and investors. By mitigating LETID loss, solar module manufacturers enhance the bankability of their products, inspiring confidence in the industry.

As solar energy continues to gain momentum as a sustainable energy source, addressing LETID loss is essential for maximizing the performance and reliability of solar modules. Ongoing research and development efforts are driving advancements in materials, passivation techniques, and testing methods, leading to more efficient and durable solar technologies.

By overcoming the challenges posed by LETID loss, the solar industry is making significant strides towards a future powered by clean and reliable renewable energy.