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Thin-film solar panels: what you need to know

Have you ever come across “flexible solar panels,” or “stick-on solar panels”? Both fit under the wider umbrella of thin-film solar panels, which is a type of solar panel technology known for being lightweight while still producing renewable solar energy. Compared to traditional solar panel cells that have the majority of the market share, thin-film solar panels are made up of electricity-producing layers that are hundreds of times thinner than typical silicon cells. 

Key takeaways

  1. There are four major types of thin-film solar panels: amorphous, cadmium telluride (CdTe), copper gallium indium diselenide (CIGS), and organic solar panels.

  2. Amorphous solar panels are more flexible but less efficient than other types of thin-film solar panels.

  3. Cadmium telluride (CdTe) is the most popular material for manufacturers of thin-film solar panels.

  4. By using the EnergySage Marketplace, you can choose from a variety of solar panel installers who are able to work with many different types of thin film panels.

What’s in this article?

Overview of thin-film solar panels

There are many different types of thin-film modules , built using a variety of materials and processes. In this article, we’ll review the four major types of thin-film photovoltaic panels — amorphous, cadmium telluride (CdTe), copper gallium indium diselenide (CIGS), and organic solar panels — and what sets each one apart from the other thin-film solar cell options. There are also experimental options like gallium arsenide (GaAs) and perovskite panels that are not yet available for consumers.

Comparison of the four main types of thin-film solar panels Solar panel typeAmorphousCdTeCIGS Organic PV Pros They use less material than traditional panels, including toxic materials. They produce higher amounts of energy than traditional panels. Their composition makes them comparable in efficiency to traditional panels. They are popular in the building-integrated panel market, making them a more affordable option. Their construction makes them extremely bendable and less susceptible to cracks. CdTe panels are less expensive to manufacture than traditional panels. Cons Amorphous panels are much less efficient than traditional panels. Cadmium is a toxic heavy metal and is necessary for the production of these panels. CIGS panels are very expensive, making them less competitive. They are still quite inefficient with efficiencies of less than 11% These panels are still much less efficient than traditional silicon panels. They also use toxic materials in their construction. The type of technology used in these panels has a shorter lifespan than others.

Amorphous solar panels

Like conventional solar panels, amorphous solar panels are primarily made up of silicon. However, though built with the same material, they are constructed in a different way: instead of using solid silicon wafers (like you’ll find in mono- or poly-crystalline solar panels), manufacturers make amorphous panels by depositing non-crystalline silicon (C-Si) on a substrate of glass, plastic, or metal. One layer of silicon on an amorphous solar panel can be as thin as one micrometer – to put that into perspective, that’s thinner than a human hair!

Advantages and disadvantages of amorphous solar panels

Amorphous solar panels have many advantages over their solar panel counterparts. For one, companies don’t need to use a lot of toxic materials to build amorphous silicon (a-si) panels – this is not always true with some other types of panels. Additionally, they require much less silicon than conventional solar panels. Amorphous solar panels are also flexible, and have significant durability, making them less susceptible to cracks than traditional panels constructed from solid wafers of silicon. Their technology is also used in smaller applications like calculators and for RV setups.

However, there are also some disadvantages to amorphous solar panel technology, the primary challenge being their efficiency — compared to conventional silicon solar cells, amorphous solar cells are typically less than half as efficient. Most types of amorphous solar panels hover around seven percent conversion efficiency, while monocrystalline or poly-crystalline solar panel arrays s on the market today can have efficiencies of over 20 percent. 

Cadmium telluride (CdTe) solar panels

Cadmium telluride (CdTe) panels are the most popular type of thin-film technology used in installations today. These panels are made up of several thin layers: one main renewable energy-producing layer made from the compound cadmium telluride, and surrounding layers for electricity conduction and collection. One of the most well-known manufacturers of CdTe panels is First Solar, an American company headquartered in Tempe, Arizona. 

Advantages and disadvantages of cadmium telluride solar panels

One of the most exciting benefits of CdTe panels is their ability to absorb sunlight close to an ideal wavelength, or shorter wavelengths than are possible with traditional silicon solar cells. Simply put, shorter wavelengths mean higher energy absorption, which is easier to convert to electricity. Plus, cadmium telluride panels are low-cost to manufacture and install compared to other types of solar panels.

However, one of the biggest concerns with CdTe panels is pollution. Cadmium is a toxic heavy metal – one of the most potent ones at that. Cadmium telluride, the compound used in these panels, also has some toxic properties. Importantly, CdTe panels are not harmful to humans or the environment as they generate electricity on rooftops, and companies take proper health precautions when handling the materials during the manufacturing process. However, the disposal of old CdTe panels continues to be a concern.

Also, like amorphous panels, cadmium telluride panels come in at lower efficiencies than other types of solar panels. Sitting around 10 to 11 percent, CdTe panels are above the efficiencies of amorphous panels, but still don’t come close to the average efficiencies of standard silicon panels.

Copper indium gallium selenide (CIGS) solar panels

CIGS solar modules  are made from a compound called copper gallium indium diselenide (try saying that five times fast!) sandwiched between conductive layers. This thin-film material goes on top of different types of base layers, such as glass, plastic, steel, and aluminum. The end result is a powerful semiconductor. Some types of CIGS panels use a flexible backing, and the thin layers allow for full-panel flexibility.

Advantages and disadvantages of CIGS solar panels

Unlike most other thin-film solar power technologies, CIGS solar panels offer competitive efficiencies to traditional silicon panels. With efficiencies exceeding 20 percent in laboratory tests, there may be a place for high-efficiency CIGS panels in the global solar panel market.

Like CdTe panels, many CIGS cells also use the toxic chemical cadmium. However, CIGS technologies use a lower percentage of cadmium, and therefore are a more environmentally-friendly choice as far as thin-film cells go – even better, some models exchange the use of cadmium for zinc.

The biggest disadvantage of CIGS panels is their price. While CIGS solar panels are an exciting technology, they remain very expensive to produce, to the point where they have a hard time competing against the more economical silicon or CdTe panels.

Organic photovoltaic cells

Organic photovoltaic (OPV) cells use conductive organic polymers or small organic molecules to produce electricity. In a cell using organic photovoltaic material, several layers of thin organic vapor or solution are deposited and held between two electrodes to carry an electrical current.

Advantages and disadvantages of organic PV cells

OPV cells are most popular among the building-integrated photovoltaic (BIPV) market. Because you can use different types of absorbers in organic cell technology, OPV devices come in a variety of colors (and can even be transparent!) This aesthetic advantage makes OPV a popular option for unique BIPV applications. Plus, the materials companies need to build organic solar cells are abundant, leading to low manufacturing costs and subsequently low market prices.

Unfortunately, like other thin-film PV options, organic photovoltaic cells currently operate at relatively low efficiencies. OPV cells typically have efficiency ratings of about 11 percent, but scaling PV module production up while keeping efficiencies high is a problem for the technology. Much of the research currently surrounding OPVs is focused on boosting its efficiency.

Another disadvantage of OPV technology is its lifespan: this technology has a shorter lifespan than both traditional panels and other thin-film options. Cell degradation that doesn’t occur in inorganic modules is an ongoing struggle for organically-based photovoltaic products.

Find your solar panel match on EnergySage

EnergySage is the nation’s leading online solar marketplace: when you register for the EnergySage Marketplace, we connect you with solar companies in your area who compete for your business with custom solar quotes tailored to fit your needs. Over 10 million people come to EnergySage each year to learn about, shop for, and invest in solar. Sign up today to see how much you can save with solar.

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