Solar panels are technologically advanced devices used to convert sunlight into electric current by the photovoltaic effect. They are made up of many photovoltaic cells, which on exposure to sunlight help generate direct current (DC) electrical power.
There are different types of solar panels with varying functions, which include — monocrystalline, polycrystalline, and thin-film solar panels, where each type of solar panel has its unique advantages and characteristics.
With the development of amorphous silicon (a-Si), Thin-film solar panels were discovered in the 1970s as an alternative to traditional crystalline silicon panels.
Thin-film solar panels are changing the landscape of renewable energy by being flexible and lightweight, and suitable for various applications, such as — building-integrated photovoltaics (BIPV), portable solar systems, and solar-powered appliances.
Let us further discuss how important it is to understand the comparison of thin-film solar panels with other types of solar panels, their different types, advantages and disadvantages.
What are thin-film solar panels?
Most commonly used materials in thin-film solar technology include — cadmium telluride (CdTe), copper indium gallium selenide (CIGS), amorphous silicon (a-Si), and a few organic photovoltaic cells (OPV).
Thin-film solar panels are formed by adding more layers of photovoltaic material to a substrate. However, this process can vary based on the material used, but it usually includes vacuum layering and chemical processes to create thin photovoltaic layers.
Being very flexibly adaptable, these Thin-film solar panels can be used in many application scenarios, including — large-scale utility projects, commercial applications, and also portable consumer products. Their flexibility and lighter weight expand their use to surfaces where traditional panels would be impractical.
There are a few benefits of thin-film solar panels that include:
- Minimized manufacturing costs.
- Less use of materials.
- Smaller carbon footprint during production.
- More flexible.
- Less prone to damage.
- Adaptable to external conditions like temperature changes and physical impact.
In comparison to traditional silicon-based panels, thin-film solar panels are considerably less efficient in converting sunlight to electricity. However, they are lighter, slightly more flexible, and are capable of performing exceptionally well in low-light conditions and extreme temperatures.
Types of Thin-Film Solar Panels
The four main types of thin-film solar panels are:
1. Amorphous Silicon (a-Si) Solar Panels: These are the widely utilized in consumer applications like calculators and watches.
2. Cadmium Telluride (CdTe) Solar Panels: CdTe panels are recognized for their excellent sunlight absorption and are used in large-scale solar installations.
3. Copper Indium Gallium Diselenide (CIGS) Solar Panels: CIGS panels deliver a high-efficiency rate. Also, these panels are perfectly suitable for both residential and commercial purposes.
4. Organic photovoltaic cells (OPV) Solar Panels: OPV cell solar panels are mostly used in transparent device, making them suitable for the building-integrated PV (BIPV) market.
These 4 types of Thin-Film solar panels are generally categorized based on the photovoltaic material used, which influences their cost, efficiency, and application.
Amorphous Silicon Solar Panels
Amorphous silicon solar panels are a specific kind of thin-film solar cell that consists of non-crystalline silicon, which makes a considerably thinner layer than traditional crystalline silicon solar cells.
They are made by placing a thin layer of silicon onto a substrate like — glass, plastic, or metal.
Amorphous silicon panels have decreasing efficiency rates, ranging between 6% to 8%, which is less compared to crystalline silicon solar panels.
Despite being less efficient, these Amorphous silicon panels perform much better in shaded conditions. Also, they have a reduced temperature coefficient compared to crystalline panels.
PROS and CONS of Amorphous silicon solar panels:
| PROS | CONS |
| Improved performance in low-light conditions | Lower efficiency |
| Highly flexible and lightweight | Less durable compared to crystalline panels |
| Requires less energy and materials to manufacture | Decreased power output |
You can learn more about amorphous silicon solar panels in detail.
Cadmium Telluride (CdTe) Panels
CdTe solar panels are made up of cadmium telluride solar cells, which is a compound used to fully capture sunlight in abundance and convert it into electrical power.
These panels are manufactured by embedding a thin layer of CdTe in between transparent conducting layers that wrap around the material, protecting them and allowing light to pass through them.
Although, CdTe panels have efficiency rates ranging between 9% to 15%. Meanwhile, a few cells in the laboratory were able to achieve up to 18.7%.
These Cadmium Telluride Panels are good at maintaining a balance between cost and efficiency, which makes them best suitable for large-scale installations.
CdTe panels are becoming popular, having held a considerable share of the thin-film solar panel market.
PROS and CONS of Cadmium Telluride (CdTe) Panels:
| PROS | CONS |
| Top-notch efficiency for thin-film technology | Utilization of toxic cadmium |
| Minimized production costs | Less efficient compared to crystalline silicon panels |
| Short energy turnaround time | Waste disposal and recycling concerns |
Copper Indium Gallium Selenide (CIGS) Panels
CIGS panels are a form of thin-film solar cell that utilizes a copper indium gallium selenide semiconductor to capture sunlight effectively and convert it into electrical current.
The process for manufacturing CIGS panels is done by embedding a thin layer of CIGS material onto a glass or plastic backing surface.
CIGS panels have commercially achieved an efficiency rate ranging between 10% to 12%, with some laboratory cells being capable of surpassing 20%.
Copper Indium Gallium Selenide Panels are known for high efficiency among thin-film panels and have a good temperature coefficient, meaning their performance doesn’t drop significantly under high temperatures.
These CIGS panels are expensive because of the indium and gallium materials used, which are extremely less abundant and are costlier than other materials.
PROS and CONS of Copper Indium Gallium Selenide (CIGS) Panels:
| PROS | CONS |
| Higher efficiency for thin-film | Higher production costs |
| Fantastic performance in varying lighting conditions | Making use of rare materials |
| Flexible and lightweight | Higher cost compared to other thin-film panels |
Organic Photovoltaic Cells
OPV are a specific type of thin-film solar panel that make use of organic molecules or polymers to transform sunlight into electrical energy.
These OPV cells are produced by the means of printing, encasing or coating the organic semiconductor materials onto a substrate.
Organic photovoltaic cells have a lower efficiency compared to other thin-film technologies, which is around 3% to 11%.
Despite these OPVs being less efficient, they are beneficial in some ways, as they can be manufactured at a much lower cost. Also, these cells offer greater flexibility and performance in various applications.
PROS and CONS of Organic Photovoltaic Cells (OPV):
| PROS | CONS |
| Very flexible and lightweight | Currently, lower efficiencies |
| Offers Possibilities of low-cost production | Not yet proven in long-term applications |
| Can be produced using a technique called roll-to-roll manufacturing | Concerns about durability |
Thin Film Solar Panels vs Traditional Solar Panels
Here is a detailed comparison between the Thin Film Solar Panels and Traditional Solar Panels in a simple table form:
| Factor | Thin Film Solar Panels | Traditional Solar Panels |
| Cost | Generally cheaper to produce | More expensive due to material costs |
| Efficiency | Lower efficiency (6% to 18%) | Higher efficiency (15% to 22%) |
| Output | Lower power output | Higher power output |
| Temperature Coefficient | Better performance at high temperatures | Performance can decrease at high temperatures |
| Lifespan | Shorter lifespan | Longer lifespan (25+ years) |
| Environmental Impact | Less energy-intensive production | Higher energy and material use in production |
| Space Requirements | Larger area needed for equivalent output | Less space needed for equivalent output |
| Aesthetics | Flexible and can be less obtrusive | Rigid and more noticeable |
| Applications | Commercial, industrial, portable products | Residential, commercial, utility-scale |
Who should buy Thin Film Solar Panels?
Thin-film solar panels are mainly suitable for large-scale commercial or industrial projects where space is not a limiting factor or problem. But they are ideal for applications where weight and flexibility are a concern, such as — curved surfaces or portable solar products.
These Thin Film Solar Panels can be used for residential purposes. However, due to their reduced efficiency, they will require a larger space to generate the same quantity of electrical power as traditional panels. So this lacking factor makes these panels not ideally suitable for all residential installations.
What Companies Sell Thin Film Solar Panels?
Many well-reputed solar companies specialize in thin-film solar panel technology, which includes — First Solar, a company which is widely recognized for its CdTe panels, and Solar Frontier, which has expertise in CIS solar panels. These companies produce a wide range of solar technology products that are great for various applications. Also, these companies are honoured for their ongoing contributions to advancing thin-film solar technology.
Here is a list of companies that sell thin-film solar panels:
- Sharp Solar
- Solar Frontier
- First Solar
- PowerFilm Solar
- Toledo Solar
- Oxford Photovoltaics
- TWI Technology Centre (Wales)
Ray is an avid reader and writer with over 25 years of experience serving various domestic and multinational private and public energy companies in the USA.