While 2026 has been a tough year for solar, there are signs that the market is recovering. New financing options and battery storage have helped. Also helping is that solar and other renewables are undeniably the future. They’re clean, they’re… renewable, and they’re getting more efficient and less expensive every day.
In this guide we look at the very backbone of the solar industry: solar panels themselves. We’ll get into the different types of solar panels available on the market today, their strengths and weaknesses, and which is best suited for specific use cases.
What is a Solar Panel?
Solar panels are used to collect solar energy from the sun and convert it into electricity.
The typical solar panel is composed of individual solar cells, each of which is made from layers of silicon, boron and phosphorus. The boron layer provides the positive charge, the phosphorus layer provides the negative charge, and the silicon wafer acts as the semiconductor.
When the sun’s photons strike the surface of the panel, it knocks out electrons from the silicon “sandwich” and into the electric field generated by the solar cells. This results in a directional current, which is then harnessed into usable power.
The entire process is called the photovoltaic effect, which is why solar panels are also known as photovoltaic panels or PV panels. A typical solar panel contains 60, 72, or 90 individual solar cells.
The 4 Main Types of Solar Panels
There are 4 major types of solar panels available on the market today: monocrystalline, polycrystalline, PERC, and thin-film panels.
Monocrystalline solar panels
Also known as single-crystal panels, these are made from a single pure silicon crystal that is cut into several wafers. Since they are made from pure silicon, they can be readily identified by their dark black color. The use of pure silicon also makes monocrystalline panels the most space-efficient and longest-lasting among all three solar panel types.
However, this comes at a cost — a lot of silicon is wasted to produce one monocrystalline cell, sometimes reaching over 50%. This results in a hefty price tag.
Polycrystalline solar panels
As the name implies, these come from different silicon crystals instead of one. The silicon fragments are melted and poured into a square mold. This makes polycrystalline cells much more affordable since there is hardly any wastage, and gives them that characteristic square shape.
However, this also makes them less efficient in terms of energy conversion and space, since their silicon purity and construction are lower than monocrystalline panels. They also have lower heat tolerance, which means they are less efficient in high-temperature environments.
Passivated Emitter and Rear Cell (PERC) panels
PERC solar panels are an improvement of the traditional monocrystalline cell. This relatively new technology adds a passivation layer in the rear surface of the cell that enhances efficiency in several ways:
- It reflects light back into the cell, increasing the amount of solar radiation that gets absorbed.
- It reduces the natural tendency of electrons to recombine and inhibit the flow of electrons in the system.
- It allows greater wavelengths of light to be reflected. Light waves over 1,180nm can’t be absorbed by silicon wafers and simply pass through, so they end up heating the cell’s metal back sheet and reduce its efficiency. The passivation layer reflects these higher wavelengths and stops them from heating up the back sheet.
PERC panels allow greater solar energy collection in a smaller physical footprint, which makes them ideal for limited spaces. They are only slightly more expensive to produce than traditional panels, due to the added materials needed, but they can be manufactured on the same equipment, and can end up having a lower average cost per watt due to their efficiency.
To get a better feel for the benefits of PERC panels, check out our blog 5 Important Benefits of PERC Solar Panels You Need to Know.
TOPCon (Tunnel Oxide Passivated Contact)
These have become much more popular for residential installs in 2025-2026, rapidly displacing PERC as the default for new installations. TOPCon adds an ultra-thin tunnel oxide layer to the rear of a monocrystalline cell, significantly reducing recombination losses. Most consumer TOPCon panels achieve 22-24% efficiency — typically 1-2 percentage points above comparable PERC panels — at a price point that has fallen dramatically as production has scaled. For most residential projects today, TOPCon is the default recommendation.
Thin-film solar panels
Thin-film panels are characterized by very fine layers that are thin enough to be flexible. Each panel does not require a frame backing, making them lighter and easier to install. Unlike crystalline silicon panels that come in standardized sizes of 60, 72, and 96-cell counts, thin-film panels can come in different sizes to suit specific needs. However, they are less efficient than typical silicon solar panels.
Thin-Film Solar Panel Variations
Unlike crystalline panels that use silicon, thin-film solar panels are made from different materials. These are:
- Cadmium telluride (CdTe)
- Amorphous silicon (a-Si)
- Copper indium gallium selenide (CIGS)
Cadmium telluride (CdTe)
CdTe has the same low-cost advantage as polycrystalline cells while possessing the lowest carbon footprint, water requirement, and energy payback time of all solar panels types. However, the toxic nature of cadmium makes recycling more expensive than other materials.
Amorphous silicon (a-Si)
Amorphous silicon panels (A-Si) derive their name from their shapeless nature. Unlike mono-and polycrystalline solar cells, the silicon is not structured on the molecular level.
On average, an a-Si cell requires only a fraction of the silicon needed to produce typical silicon cells. This allows them to have the lowest production cost, at the expense of efficiency. This is why a-Si panels are suited for applications that require very little power, such as pocket calculators.
Copper indium gallium selenide (CIGS)
CIGS panels use a thin layer of copper, indium, gallium, and selenium deposited on a glass or plastic backing. The combination of these elements results in the highest efficiency among thin-panel types, though still not as efficient as crystalline silicon panels.
Solar Panel Types by Efficiency
Among all panel types, crystalline solar panels have the highest efficiency.
- Monocrystalline panels have an efficiency rating over 20%.
- PERC panels add an extra 5% efficiency thanks to their passivation layer.
- Polycrystalline panels hover somewhere between 15-17%.
In contrast, thin-film panels are usually 2-3% less efficient than crystalline silicon. On average:
- CIGS panels have an efficiency range of 13-15%.
- CdTe ranges between 9-11%.
- a-Si have the lowest efficiency at 6-8%.
| Panel type | Efficiency |
| PERC | 20-22% |
| TOPCon | 22-24% |
| Monocrystalline | 20-22% |
| Polycrystalline | 15-17% |
| Copper indium gallium selenide (CIGS) | 13-15% |
| Cadmium telluride (CdTe) | 9-11% |
| Amorphous silicon (a-Si) | 6-8% |
Solar Panel Types by Power Capacity
Monocrystalline cells have the highest power capacity, thanks to their single-crystal construction that allows a higher output rating in a smaller package. Many monocrystalline panels can generate up to 400–500W+ for most modern residential panels.
Recent advances in solar technology have allowed polycrystalline panels to bridge the gap. A standard 60-cell polycrystalline panel is capable of producing between 300W or more. However, monocrystalline panels still beat polycrystalline in terms of power capacity per cell.
Because thin-film panels don’t come in uniform sizes, there is no standard measure of power capacity, and the capacity of one thin-film panel will differ from another based on its physical size. In general, given the same physical footprint, conventional crystalline panels output more power than a thin-film panel of the same size.
Solar Panel Types by Cost
Monocrystalline panels (or modules as they are technically known) carry a hefty price tag, due to their energy-intensive and inefficient manufacturing process with only a 50% yield for every silicon crystal.
Polycrystalline modules are cheaper because they make use of the crystal fragments leftover from monocrystalline production, which results in a simpler manufacturing process and lower production costs.
Among thin-film solar panels, CIGS is the most expensive, followed by CdTe and amorphous silicon. Apart from the lower acquisition cost, thin-film modules can be easier to install thanks to their lighter weight and flexibility, which lowers the cost of labor.
While the total cost of residential systems has declined by more than 65% over the last decade, the soft cost of a system has actually risen from 58% of total system cost in 2014 to 65% in 2020.
For more information about soft costs, check out our article on the soft costs in the solar industry, and what’s being done to reduce them.
Other Factors to Consider
Temperature
The temperature of a solar panel can affect its ability to generate energy. This loss of output is reflected through the temperature coefficient, which is a measure of the panel’s decrease in power output for every 1°C rise over 25°C (77°F).
Monocrystalline and polycrystalline panels have a temperature coefficient between -0.3% / °C to -0.5% / °C, while thin-film panels are closer to -0.2% / °C. This means that thin-film panels can be a good option for hotter environments or places that experience more sunlight throughout the year.
Fire rating
The updated International Building Code of 2012 requires solar panels to match the fire rating of the roof where they are installed. This is to ensure that the modules do not accelerate the spread of flames in the event of a fire. (California goes one step further by requiring the whole PV system, which includes the racking system, to have the same fire rating).
As such, solar panels now carry the same classification rating as roofs:
Class A
- effective against severe fire test exposure
- flame spread should not exceed 6 feet
- required for wildland-urban interface areas, or areas with high fire severity and wildfire risk
Class B
- effective against moderate fire test exposure
- flame spread should not exceed 8 feet
Class C
- effective against light fire test exposure
- flame spread should not go beyond 13 feet
Hail rating
Solar panels are also tested for hail impacts.
UL 1703 and UL 61703 standards address hail storms, by dropping 2-inch solid steel spheres on solar panels from a height of 51 inches, and by firing 1-inch ice balls on PV panels with a pneumatic cannon to simulate hail impacts.
Because of their thicker construction, crystalline panels can withstand hail hitting at speeds of up to 50mph, while thin-film solar panels carry a lower rating due to their thin and flexible nature.
Hurricane rating
While there is no formal solar classification rating for hurricanes, the Department of Energy recently expanded its recommended design specifications for solar panels to safeguard against severe weather.
The new recommendations include:
- Modules with the highest ASTM E1830-15 rating for snow and wind loading in both the front and back.
- Fasteners with true locking capability based on DIN 65151 standard
- The use of through-bolting modules with locking fasteners instead of clamping fasteners
- The use of 3-frame rail systems for improved rigidity and support against twisting
- Tubular frames over open-shaped C channels
- Perimeter fencing around PV systems to slow down wind forces
Light-Induced Degradation (LID)
LID is a performance loss commonly seen in crystalline panels during the first few hours of sun exposure. This happens when sunlight reacts with oxygen traces left over from the manufacturing process, which affects the silicon lattice structure.
The LID loss is directly tied to the manufacturing quality and can range from 1-3%.
Summary: Solar Panel Types Compared
| TOPCon | PERC | Monocrystalline | Polycrystalline | Thin-film | |
| Initial Cost | High | Highest | High | Middle | Highest to lowest: CIGSCdTea-Si |
| Efficiency | 22-24% | 20-22% | 20-22% | 15-17% | CIGS: 13-15%CdTe: 9-11%a-Si: 6-8% |
| Appearance | Black with rounded edges | Black with rounded edges | Black with rounded edges | Blue with square edges | Depends on the thin-film variant |
| Advantages | Highest efficiency, popular in new installs, falling cost, excellent warranty coverage | Requires least space, very efficient, Highest power capacity | Less expensive alternative to PERC panels without the passivating layer | Middle option in terms of cost, efficiency and power capacity | Lowest costEasier to install |
| Disadvantages | Higher initial cost than mono | Most expensive initially Some earlier panels suffered from light and elevated temperature induced degradation | High initial cost, Low yield in the manufacturing process | Low heat tolerance, not suitable in hot environments | Shorter lifespan than crystalline panels requires more spaceLeast efficient |
So, Which Solar Panel Type Should You Use?
As crystalline and thin-film panels have their own pros and cons, the choice of solar panel ultimately comes down to your specific property and condition settings.
Limited Space
Those living in a dense area with limited space should opt for highly efficient monocrystalline modules to make the most of the physical space and maximize utility savings. If budget permits, going for PERC panels can lower energy generation costs even more in the long run.
Large Properties
Those with a sufficiently larger property can save on upfront costs by using polycrystalline solar panels, where a bigger panel footprint can offset the lower panel efficiency. However, a larger footprint could also mean added labor costs, so it’s not necessarily cheaper to get a higher quantity of less expensive panels. While the initial cost may be low, it may eventually be offset by reduced efficiency and higher operating expenses in the long term.
As for thin-film solar panels, these are best suited for locations where the heavy and labor-intensive installation of crystalline silicon is not feasible. Such locations can include commercial buildings with tight spaces or thin roofs; compact spaces such as recreational vehicles and watercraft; and areas that require flexible installation instead of rigid paneling.
Keep in mind that solar panels are designed for long-term installation, which can be as long as 25 years. So whatever type you choose to go with, make sure to do your homework to ensure that it’s the best option for your needs.
Frequently asked questions
Q: What type of solar panel is best for residential installations in 2026?
For most residential installations, TOPCon monocrystalline panels are the current best choice — they offer the highest efficiency (22-24%), strong warranties, and have come down significantly in price as production has scaled. PERC panels remain a solid and slightly more affordable alternative. Polycrystalline panels are increasingly rare in new residential installs due to their lower efficiency and the falling cost of monocrystalline options.
Q: What is the difference between PERC and TOPCon solar panels?
Both PERC and TOPCon build on standard monocrystalline cell technology, but use different approaches to reduce energy loss. PERC adds a passivation layer to the rear of the cell to reflect unused light back through the cell. TOPCon adds an ultra-thin tunnel oxide layer that more effectively prevents electron recombination, resulting in higher efficiency — typically 1-2 percentage points above comparable PERC panels. TOPCon has largely replaced PERC as the dominant residential panel technology.
Q: Are thin-film solar panels suitable for residential use?
In most cases, no. Thin-film panels (CdTe, CIGS, a-Si) have significantly lower efficiency ratings than crystalline silicon panels, meaning they require more roof space to generate the same output. They’re better suited for large commercial or utility-scale projects where space isn’t a constraint, or for specialized applications like portable or flexible installations. For most residential rooftops, monocrystalline or TOPCon panels are a much better fit.
Q: How do I choose between panel types for a specific installation?
The key factors are available roof space, budget, and local climate. Space-constrained rooftops benefit most from higher-efficiency TOPCon or PERC panels, where every square foot matters. For larger installations with ample roof space, polycrystalline panels can offer a lower upfront cost — though their lower efficiency may not save money in the long run. Aurora’s design platform lets you model different panel types side by side to compare production output and economics for any specific address.
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