Which type of solar panel should you choose?

Solar technology has come a long way from bulky, expensive panels with limited output. Over the last century, it has evolved toward higher efficiency, lower cost, and better durability. Today, there are three types of solar panels: monocrystalline, polycrystalline, and thin-film. 

The market has largely reached a verdict on which to use. For a traditional rooftop solar panel system, monocrystalline is the right choice for nearly every homeowner. Panel prices have come down enough that the old cost argument for polycrystalline no longer applies. If you're planning a portable setup on an RV or boat, thin-film solar panels remain the best option.

Here's how to find panels that make the most sense for you.

There are three main types of solar panels: monocrystalline, polycrystalline, and thin-film. 

If you’re installing solar in 2026, you’re probably only going to be presented with monocrystalline panel options. They’re more efficient and no longer much more expensive than polycrystalline panels, which is why they’ve become the standard for residential solar. But if you installed your system 10 years ago, there’s a good chance you have polycrystalline panels—and they still work just fine. Today, the real decision isn’t usually between monocrystalline and polycrystalline, but whether a standard rooftop system or a more specialized thin-film setup makes sense for your needs.

Pros and cons of different types of solar panels

Each panel type carries a different price tag, driven mainly by differences in manufacturing.

Monocrystalline solar panels: Historically, the most expensive per panel

Monocrystalline panels cost more because each cell is cut from a single pure silicon crystal in a process known as the Czochralski method. It's energy-intensive and produces some silicon waste. (That leftover silicon gets melted down to make polycrystalline cells, so it doesn't all go to waste).

That said, the higher per-panel costs are increasingly offset by efficiency gains. According to the Department of Energy’s solar cost benchmarks, a 21% efficiency rating is the residential industry standard as of 2024. In other words, you need fewer panels to generate the same power, which reduces hardware and labor costs. 

Polycrystalline solar panels: A lower upfront cost, but a fading option

Polycrystalline panels are generally cheaper to produce compared to monocrystalline panels because their cells are made from melted silicon fragments rather than a single grown crystal. For a long time, the simpler process meant lower overall costs for manufacturers and homeowners alike.

But the math has shifted. Over the last decade or so, monocrystalline modules have become even more efficient while prices have fallen sharply. As a result, the cost-per-watt gap between mono and poly shrank to the point where poly's efficiency disadvantage became hard to justify. Now, most major manufacturers have moved their residential lines to exclusively monocrystalline cells.

Thin-film solar panels: It depends

Thin-film panel costs vary by material. Cadmium telluride (CdTe) panels (the type made by First Solar) are among the cheapest per watt to manufacture and dominate the utility-scale market. Copper Indium Gallium Selenide (CIGS) panels cost more to produce than CdTe.

For residential use, thin-film is almost never used for rooftop installations. While these panels are lighter and easier to handle than mono or poly cells—which can lower installation labor on certain project types— monocrystalline panels are now cost-competitive enough that thin-film rarely wins on total installed solar panel cost for a standard rooftop system. 

The real advantage is portability and flexibility, not price. Thin-film panels are the right call for portable systems on RVs and boats, or for unconventional roof types where weight or portability matters more than efficiency.

Efficiency determines how much electricity your panels generate per square foot of roof space. If you have limited roof space, choose high-efficiency panels to get the most out of your system.

Crystalline solar panels: High efficiency

Monocrystalline panels are the efficiency leaders, and the technology has improved fast over the last couple of decades. According to Lawrence Berkeley National Laboratory's Tracking the Sun report, median module efficiency in residential installations climbed from 13.5% in 2002 to over 20% by 2022—and it’s continued to rise since then. Today's residential mono panels typically fall between 20% and 23%, with most putting out 400 to 450 watts. 

Monocrystalline panels also perform better in the heat. Lower temperature coefficients mean they maintain more of their rated output on hot days, which is an advantage if you live somewhere with long, warm summers.

Polycrystalline panels typically have an efficiency of 15% to 17%. With monocrystalline prices where they are, polycrystalline isn't a standard option from most residential installers.

Modern monocrystalline cell technologies: PERC, TOPCon, HJT, and IBC

Not all monocrystalline panels are the same under the glass. The dominant cell architecture has changed over the past few years:

When comparing quotes, ask what cell technology the proposed panels use. TOPCon and HJT panels typically carry stronger efficiency and degradation warranties than older PERC models.

Thin-film solar panels: Lower efficiency for residential use

Thin-film efficiency varies significantly by material. CdTe modules from First Solar, designed for utility-scale solar farms rather than rooftops, reach up to 19.7% module efficiency. That's competitive with some crystalline panels, but these are large-format panels for massive projects.

The flexible CIGS and amorphous silicon (a-Si) thin-film panels that are available for residential and portable use typically have efficiencies of 11 to 16%. Because thin-film doesn't come in standardized sizes, power output varies with the physical size of the equipment. 

Per square foot, monocrystalline panels will outperform residential thin-film options.

Solar cells use a semiconducting material that converts sunlight into electricity by turning photons into electrons. Silicon is the most common semiconductor in solar manufacturing.

What are crystalline solar panels made of?

Both monocrystalline and polycrystalline panels are built from silicon wafer cells arranged in rows and columns, covered with a glass sheet, and framed. The key difference is in the silicon.

Monocrystalline cells are cut from a single pure silicon crystal. Polycrystalline cells are cast from melted silicon fragments poured into a mold. That distinction produces the visual difference you see: Mono cells look uniform and black, while poly cells have a fragmented, speckled appearance.

What are thin-film solar panels made of?

Unlike crystalline panels, thin-film can be made from several different materials:

• Cadmium telluride (CdTe) is the most widely manufactured type. A CdTe layer sits between transparent conducting layers, with glass protection on top. This technology is used almost exclusively for utility-scale projects in the U.S.

• Amorphous silicon (a-Si) uses non-crystalline silicon applied to glass, plastic, or metal. These panels are thinner and more flexible than crystalline panels but less efficient.

• Copper Indium Gallium Selenide (CIGS) uses a semiconductor made from four elements attached to a conductive substrate of glass, nylon, aluminum, or steel. Electrodes on the front and back capture electrical current. CIGS is more efficient than a-Si but costs more to produce.

Monocrystalline solar panels are typically black

Black solar panels are almost certainly monocrystalline. Light interacts with the pure silicon crystal to create the dark appearance. Back sheets and frames come in black or silver, and all-black panels (black cells, black frame, black back sheet) have become a popular aesthetic choice for homeowners who want their panels to blend into a dark shingle roof.

Polycrystalline solar panels are blue

Polycrystalline panels have a distinctive blue hue because light reflects differently off fragmented silicon crystals. Frames are typically silver, while back sheets are silver or white. 

Thin-film solar panels have a low-profile

Thin-film cells are roughly 350 times thinner than the crystalline wafers used in mono or poly panels. Adhesive thin-film products lie nearly flush with the surface, while framed thin-film panels can reach a similar total thickness to crystalline panels. Depending on their material, thin-film panels appear in blue or black and are often hard to spot from the street.

For most homeowners installing a rooftop solar panel system, monocrystalline is the answer—and likely the only option you’ll be presented. As the most efficient type available, it's what nearly every residential installer uses today, and prices have come down to the point where the old cost-savings argument for polycrystalline no longer applies.

If you have a large commercial roof with weight restrictions, or you're putting together a portable or DIY solar setup for an RV or boat, thin-film is worth exploring. It's lighter, more flexible, and built for unconventional installations.

Polycrystalline panels are what you'll find on systems installed before roughly 2020. If you have them, they'll continue to perform well for years. For new installations, though, they're rarely an option, and rarely the right choice.