The Quick Guide To Thin-Film Solar Panels

If you’re researching solar panels for your home, the still-evolving category of thin-film solar panels likely isn’t what you’re looking for. Still, there are many other reasons why homeowners should know about thin-film photovoltaic (PV) cells.

Let’s take a close look at thin-film solar technology to understand how it works and see how it might be the future of renewable energy.

What Are Thin-Film Solar Panels?

Thin-film PV cells don’t use the same crystalline silicon as other solar panels. They’re made of a semiconducting material, which varies by the types we’ll discuss below. They also use a conductive sheet and a protective layer. The goal of thin-film solar panels is to offer a less expensive, flexible, easily manufactured way to go solar. There’s still work to do to bring costs down, but thin-film solar panels can flex and stick to a variety of surfaces.

While monocrystalline solar ingots might be three-tenths of a millimeter thick, a thin-film solar cell is thinner than a human hair. That allows it to be flexible, opening many possibilities for use. The downside is that thin-film solar panels range from just 7% to 18% efficiency, where traditional panels boast an efficiency of 20% or more.

How Do Thin-Film Solar Panels Work?

With their low-temperature coefficient, thin-film solar panels tend to retain their efficiency in high temperatures. Crystalline solar panels are known for losing efficiency as the mercury rises.

On the other hand, thin-film solar cells don’t last as long as their crystalline counterparts. They also require more space to get the same amount of electricity as the more efficient crystalline panels.

Crystalline Solar Cells Vs. Thin-Film Solar Cells

Along with thin-film are two other main categories of solar panel technologies. Here’s a quick overview of monocrystalline and polycrystalline cells and how they differ from thin-film cells.

Thin-Film Solar Panels Vs. Monocrystalline Solar Panels

Monocrystalline solar panels are made from a single ingot of pure crystalline silicon, which is used in many other semiconductor technologies. Typically, monocrystalline cells are known for their high efficiency, with a range of 17% to 23% efficiency in converting solar energy into electricity. This cell type is also the most expensive option and has a rigid structure, unlike the flexible structure of many thin-film modules. 

Deciding between monocrystalline and polycrystalline cells is a common consideration for homeowners investing in a solar array.

Thin-Film Solar Cells Vs. Polycrystalline Solar Cells

Fragments of silicon are melted together to form ingots for polycrystalline cells, which are then sliced into wafers. Polycrystalline cells are usually 15% to 17% efficient. Thin-film cells that are efficient may be more expensive than polycrystalline cells. Like monocrystalline photovoltaic cells, polycrystalline cells have a rigid structure and can’t match the flexibility of thin-film technology.

Types Of Thin-Film Solar Panels

Thin-film panels are available with varying characteristics. In many cases, the differences between each type make them particularly suited for certain applications. Let’s examine the types of thin-film technology, along with their pros and cons.

Copper Indium Gallium Selenide Is Light, Efficient And Expensive

Lightweight and with efficiency typically in the 10% to 12% range, copper indium gallium selenide (CIGS) panels can work well on aircraft and other forms of transportation. They’re available with flexible backing, allowing them to be mounted in a variety of spaces. CIGS cells have also reached more than 22% efficiency in laboratory conditions.

Aside from the expense, the cadmium sulfide buffer layer in CIGS panels is toxic and carcinogenic to humans. If researchers overcome this issue, CIGS cells could carry even more value as a solar technology.

Cadmium Telluride Is Great For Low Prices But Lags In Efficiency

For cheaper cells, cadmium telluride (CdTe) cells are a solid option. They’re typically 9% to 11% efficient in real-world applications, but they’ve reached nearly 19% in lab tests. CdTe panels require extra caution during the manufacturing process, and end-of-life disposal is necessary to safely handle the toxic cadmium in the cells.

Amorphous Silicon Is Durable And More Eco-Conscious

With excellent durability and fewer toxic materials than other thin-film cells, amorphous silicon (a-Si) cells offer an excellent option for consumer electronics. At around 7% efficiency, though, they’re behind the other types of thin-film cells.

Amorphous silicon cells are often used in building-integrated photovoltaic projects, which we’ll discuss shortly.

Where Do Thin-Film Solar Cells Work Best?

Most home solar projects rely on either monocrystalline or polycrystalline solar modules. When is thin-film the right option?

Utility Scale And Commercial Projects

When there’s plenty of space on a rooftop or on the ground, thin-film solar panels can be a terrific solution because of their low costs and light weight. That usually means solar farms and industrial roof space. Homeowners typically need to get as many kilowatt-hours (kWh) from their limited roof space as possible. That makes thin-film an inferior proposition for homes – at least for now.

Building-Integrated Photovoltaics

With building-integrated photovoltaics (BIPV), architects can now work a photovoltaic array directly into a building’s design. Rather than racking and conventional panels, BIPV allows solar cells to be part of a building’s facade, window glazing or roofing tiles.

This can help overcome the occasional aesthetic objections to solar panel installations.

Vehicles

Because of their flexible structure, thin-film solar modules are a good fit for powering vehicles, especially as electric vehicle technology evolves. RV and boat owners could add solar power to them even on curved surfaces, thanks to thin-film solar cells.

Portable And Consumer Electronics

With its compact size and low weight, thin-film solar technology is a nice fit for portable electronics. From the early days of solar-powered calculators to today’s camping lanterns, power banks and laptop computers, thin-film solar is a solid solution for powering your favorite electronics away from home.

FAQs: Thin-Film Solar Panels

These are a few common questions from people interested in thin-film solar panels.

Should I get thin-film solar for my house?

It depends on your roof space and aesthetic demands. In most cases, monocrystalline or polycrystalline solar panels are a better option, especially for retrofitting. If you’re thinking of building a new house and have ample budget, building-integrated photovoltaics could be an option. 

Do thin-film solar panels last as long as monocrystalline and polycrystalline panels?

Typically, thin-film solar panels have a lifespan of 10 to 20 years. That’s a wide range, but also significantly shorter than other types of panels, which often have lifespans of more than 20 years.

Are thin-film solar panels good for metal roofs?

Thin-film solar panels can be great for a metal roof. With adhesive backing rather than conventional racking, you could have an aesthetically pleasing solar roof.

The Bottom Line: Thin-Film Solar Technology Has Its Place, But It’s Not A Fit For Most Homeowners

Thin-film solar panel technology is still evolving. If the products can improve in their efficiency and eco-friendliness, they’re likely to gain market share and more space on homeowners’ rooftops. For now, they’re best suited for more specialized applications.