What are Thin-Film Solar Panels? – Everything You Need to Know

Solar panels are the talk of the town. Similar to other types of panels, thin-film solar panels are gaining prominence in the renewable industry. They are cheaper and faster to manufacture with no overhead expenses. 

In this article, we will try to answer the question, “What are thin-film solar panels” and explore everything you need to know about thin-film panels.

Let’s begin with the basic definition of solar panels.

What are Thin-Film Solar Panels?

How do these panels work? These solar panels are a type of photovoltaic technology that utilizes thin layers of semiconductor materials to convert sunlight into electricity. 

Unlike conventional solar panels, which are typically made of crystalline silicon, these employ various thin-film materials, such as amorphous silicon, cadmium telluride, and copper indium gallium selenide (CIGS). This unique construction allows for flexibility and a more efficient use of materials.

Composition of Thin-Film Solar Panels

Understanding what are thin-film solar panels and their composition is crucial to grasp their functionality. Typically, these panels consist of several layers, each serving a specific purpose in the energy conversion process. 

The layers include a substrate, a semiconductor layer, a transparent conducting layer, and a protective top layer. The flexibility of thin-film panels enables their application in diverse settings, including curved surfaces and flexible materials.

Now, let’s cover the main advantages of the solar panels.

What are Thin-Film Solar Panels – Advantages

Here is a breakdown of the advantages of these panels.

1) Cost-Effectiveness 

The cost of thin films vs crystalline solar panels depends on a few factors. What sets them apart is their cheaper manufacturing process. The materials used are less expensive than traditional crystalline silicon, making them a viable option for large-scale solar projects.

2) Flexibility 

The flexibility of thin-film panels allows for unconventional applications, such as integration into building materials or curved surfaces. This characteristic expands the possibilities for solar energy utilization in various industries.

3) Lightweight

Thin-film solar panels are generally lighter than traditional solar panels, making them suitable for installations where weight is a critical factor, such as on rooftops.

4) Efficiency in Low-Light Conditions

How much power a thin-film solar panel can produce? Thin-film technology often exhibits better performance in low-light conditions compared to traditional panels. This makes them a preferable choice in areas with varying weather patterns. There are high efficiency rates of 10 to 12%.

Next, we shall move to the multiple applications of the solar panels.

Applications of Thin-Film Solar Panels:

Thin-film solar panels find applications in a wide range of settings, including:

1) Building-Integrated Photovoltaics (BIPV): Integrating thin-film solar panels into building materials like windows, roofing, and facades enables sustainable energy generation without compromising aesthetics.

2) Portable Devices: The flexibility and lightweight nature of thin-film panels make them ideal for powering portable devices, such as solar chargers for smartphones and laptops.

3) Off-Grid Solutions: In remote or off-grid locations, where traditional energy infrastructure is unavailable, thin-film solar panels provide a reliable source of electricity.

4) Large-Scale Solar Farms: Due to their cost-effectiveness and ease of manufacturing, thin-film solar panels are increasingly being used in large-scale solar farms to generate grid-connected electricity.

Now that’s sorted. Let’s check out certain limitations of thin-film solar panels.

Challenges and Considerations:

While thin-film solar panels offer various advantages, it’s essential to note the challenges of the panels.

Lower Efficiency: Generally, thin-film panels have lower efficiency compared to traditional solar panels. This means a larger surface area is required to generate the same amount of electricity.

Degradation Over Time: Some thin-film materials may experience degradation over time, impacting the long-term performance and durability of the panels.

Toxic Materials: Certain thin-film materials, such as cadmium telluride, raise environmental concerns due to their toxicity. Proper recycling methods are crucial to mitigate potential environmental impacts.

Moving on, let’s explore the ways through which these are made.

How Are Thin-Film Solar Panels Made

These panels are a remarkable advancement in solar technology, offering a flexible and cost-effective alternative to traditional crystalline silicon panels. Understanding the manufacturing process sheds light on the uniqueness of these panels and their potential to revolutionize the solar energy landscape.

I) Substrate Selection:

The manufacturing of thin-film solar panels begins with the selection of a substrate—a base material onto which the subsequent layers will be deposited. Common substrate materials include glass, metal, or flexible materials like plastic. The choice of substrate depends on the intended application and the desired characteristics of the final solar panel.

II) Deposition of Semiconductor Material:

The semiconductor layer is a critical component of thin-film solar panels, responsible for converting sunlight into electricity. Several semiconductor materials are utilized in this process, including amorphous silicon, cadmium telluride, and copper indium gallium selenide (CIGS). Each material has unique properties that influence the efficiency and cost of the solar panel.

• Amorphous Silicon (a-Si): In the case of amorphous silicon, a non-crystalline form of silicon is deposited onto the substrate using techniques like chemical vapor deposition (CVD) or physical vapor deposition (PVD). This layer is typically thin, allowing for flexibility and a lower material cost.
• Cadmium Telluride (CdTe): Cadmium telluride is a compound semiconductor that is deposited onto the substrate using a process called sputtering. This technique involves bombarding a target material with high-energy particles, causing atoms to be ejected and deposited onto the substrate.
• Copper Indium Gallium Selenide (CIGS): CIGS is a compound made from copper, indium, gallium, and selenium. The deposition of CIGS is often carried out using processes like sputtering or electrodeposition. This material is known for its high absorption coefficient, allowing for efficient light absorption and electricity generation.

III) Transparent Conducting Layer:

On top of the semiconductor layer, a transparent conducting layer is applied. This layer is typically made of materials like indium tin oxide (ITO) or other conductive oxides. The layer serves multiple purposes, such as facilitating the flow of electricity and allowing sunlight to reach the semiconductor surface.

IV) Back Contact and Encapsulation:

To complete the structure of the thin-film solar panel, a back contact layer is applied. This helps in efficiently collecting the generated electricity and conducting it to the external circuit. Additionally, a protective encapsulation coating is added to shield the solar cells from environmental factors such as moisture and contaminants. This is crucial for the long-term durability and performance of the solar panel.

A Glimpse into Manufacturing Techniques:

The deposition of thin films and the creation of layers involve various manufacturing techniques, each contributing to the efficiency and characteristics of the final product. Some of the common techniques include:

I) Chemical Vapor Deposition (CVD): This process involves the chemical reaction of gases to deposit a thin film onto the substrate. It is commonly used in the production of amorphous silicon thin-film solar panels.

II) Sputtering: Sputtering involves the ejection of material from a target source through ion bombardment. This technique is frequently used for depositing materials like cadmium telluride and CIGS.

III) Electrodeposition: In this process, a thin film is formed through the electrodeposition of materials onto the substrate. It is often employed in the production of CIGS thin-film solar panels.

IV) Testing and Quality Control: Once the manufacturing process is complete, thin-film solar panels undergo rigorous testing and quality control measures. This ensures that each panel meets specified efficiency standards and is free from defects. Testing may include measures of electrical performance, durability, and resistance to environmental factors.

Finally, let’s cover the commonly asked questions about what are thin-film solar panels.

FAQs – What are Thin-Film Solar Panels?

How are CIGS thin-film solar panels made?

CIGS thin-film panels are made with copper, indium, and galium which are then sealed into a deposit of selenide vapor. 

Do buses have thin-film solar panels?

Electric buses have solar rooftop compartments. The thin-film panels help to cool down the temperature of the compartment. There is a thick heat insulation layer that extracts the hot air emanating from the engine. 

Are thin-film solar cells better than silicon solar cells?

Yes, indeed. Silicon cells absorb sunlight from a vast spectrum allowing greater electricity conversion and higher efficiency. 

Are thin-film solar cells better than mono-crystalline solar cells?

Thin film panels generate less power than monocrystalline solar panels. A mono panel is highly efficient and requires less surface area to produce the same amount of power as a thin-film panel. 

How long do thin-film solar panels last?

Thin-film solar panels usually last 10 to 20 years. They have the fastest payback period but a relatively shorter lifespan than mono and poly solar panels. 

What are the advantages and disadvantages of thin-film solar panels?

The key benefits include high-efficiency rate, and power generation in low light conditions. On the other hand, limitations include higher manufacturing costs and solar cell degradation. 

How much do thin film solar panels cost?

The pricing varies greatly. However, the average cost of a thin film solar ranges around $1 – $1.5 per watt. There are variable expenses like installation costs and the shipment of CIGS panels.

Conclusion:

In conclusion, understanding what are thin-film solar panels opens up a world of possibilities for sustainable energy solutions. Their cost-effectiveness, flexibility, and diverse applications make them a compelling choice in the quest for clean and renewable energy. As technology continues to advance, thin-film solar panels are likely to play a pivotal role in shaping the future of solar energy.

Do you want to enter the solar industry, get in touch with Sustvest to gain insightful trends and stay updated about the latest solar news in India.