Amidst the global energy transition and growing environmental awareness, green energy has become an integral part of our lives. Photovoltaic curtain walls, a type of green building that converts solar energy into electricity, are developing at an unprecedented rate. With its high photoelectric conversion rate, excellent transmittance, and wide range of applications, CdTe solar-generating glass presents a promising market prospect in the field of building-integrated photovoltaics (BIPV).

How to choose the right CdTe solar-generating glass product and its transmittance directly impacts its power generation efficiency and practical application. Let's take a look at CdTe solar-generating glass products from Zoom Solar Green Energy Technology as an example.

1 Basic Principles and Characteristics of CdTe Solar-generating Glass

CdTe solar-generating glass is made by dissolving cadmium telluride and cadmium sulfide at high temperatures into the glass surface, then cutting it into cell modules using nano-lasers. Cadmium telluride (CdTe) thin films are deposited on a glass substrate to form a photovoltaic layer. When sunlight strikes the CdTe film, photons are absorbed and excited to release electrons, generating an electric current and achieving photoelectric conversion. Its core structure is relatively simple, consisting of five layers: a glass substrate, a transparent conductive oxide (TCO) layer, a cadmium sulfide (CdS) window layer, a cadmium telluride (CdTe) absorber layer, a back contact layer, and a back electrode.

Currently, CdTe-based solar glass has the highest market share in thin-film photovoltaic modules, accounting for over 95% of all thin-film modules. Its advantages can be summarized as follows:

1. Cadmium telluride has a bandgap of 1.45 eV, making it the best solar cell absorber material for the terrestrial solar spectrum.

2. Excellent low-light performance: Because Cadmium telluride is a direct-gap material, it absorbs well across the entire spectrum. Therefore, its performance in low-light conditions, such as early morning, evening, and on rainy and snowy days, is significantly superior to that of crystalline silicon cells made of indirect bandgap materials, reaching 100 times that of silicon.

3. Low temperature coefficient: The temperature coefficient of the Cadmium telluride solar cell produced by Zoom Solar Green Energy Technology is approximately -0.19%/°C, compared to -0.45%/°C for crystalline silicon cells. This means that in high-temperature and high-humidity environments, Cadmium telluride solar cell loses less power and offers significant advantages in power generation performance.

4. Minimal hot spot effect: In partial shade, the vertical scribe line design of Cadmium telluride cells minimizes power loss, significantly improving power generation capacity, ensuring product life, and ensuring safety.

5. Uniform Color, Elegant Appearance: Zoom Solar Green Energy Technology's standard CdTe solar glass modules measure 1200 x 1600 mm. These products offer uniform color, a beautiful appearance, and a strong overall appearance, making them particularly suitable for buildings requiring high aesthetic standards.

6. High Power Generation Efficiency: With a photoelectric conversion efficiency of 17%, these modules significantly outperform crystalline silicon cells made of indirect bandgap materials in low-light conditions such as early morning and evening. They also offer a long operating life, generating approximately 3-8% more power than traditional products of the same installed capacity.

7. High Degree of Customization: Color, pattern, shape, size, and transmittance can be flexibly customized to meet specific needs, making them a perfect alternative to traditional building materials.

2. CdTe Solar Glass Product Transmittance Options

Transmittance is a key indicator of the visible light transmittance of CdTe solar glass. During production and processing, different de-filming techniques are used to achieve varying transmittances. Three common de-filming techniques are chemical de-filming, physical de-filming, and laser de-filming. Zoom Solar Green Energy Technology's CdTe solar glass uses laser de-filming technology to ensure that the de-filming effect and glass quality meet user requirements.

In practical applications, the light transmittance of CdTe solar glass not only affects daylighting but also directly impacts the glass's power generation output and efficiency. Specifically, the higher the light transmittance of CdTe solar glass, the lower its power generation efficiency. Conversely, low light transmittance glass offers higher power generation efficiency, but excessively low light transmittance can result in insufficient light inside the building, impacting operational efficiency. Therefore, when selecting the light transmittance of solar glass, it's important to consider the following points to maximize its efficiency and bring more green energy to our lives.

1.0 Light Transmittance CdTe Solar Glass

In applications where light transmittance is not a requirement, such as rooftops of large centralized power stations, industrial and commercial plants, inter-story and shear wall structures of urban buildings, and distributed power station applications such as photovoltaic storage and charging carports, opaque CdTe solar glass can be selected. This type of solar-generating glass features low cost and high power generation capacity, allowing more sunlight to directly reach the glass, improving power generation efficiency.

2.20% Transmittance CdTe Solar Glass

For applications requiring both daylighting and power generation, such as photovoltaic sunrooms, photovoltaic skylights, and corridors, we can choose CdTe solar-generating glass with 20% transmittance. This not only meets daily daylighting needs but also harnesses solar energy for power generation, achieving the dual benefits of daylighting and power generation.

3.50% Transmittance CdTe Solar Glass

For locations requiring higher visible light transmittance, such as photovoltaic sunrooms and skylights, CdTe solar-generating glass with 50% transmittance can be selected. It balances light transmission, heat insulation, and power generation, effectively reducing indoor heat loss and improving living comfort.

Furthermore, prices for CdTe solar glass vary depending on its transmittance. Generally speaking, higher transmittance translates to higher costs, so product selection should be tailored to your budget.

3 Conclusion

As a new generation of green building materials, CdTe solar glass has become a significant force in the green energy sector due to its high photoelectric conversion rate, excellent light transmittance, and wide range of applications. In practical applications, it's crucial to scientifically and rationally select the appropriate product based on your specific needs. As a practitioner, Zoom Solar Green Energy Technology will continue to explore and innovate new application scenarios and technical approaches to promote the sustainable development and progress of China's green energy industry.