Types of Solar Panels

The decision to convert your home to solar power may have been an easy one. Not only is solar energy good for the planet—it reduces our dependence on fossil fuels—but it is also good for your wallet as you reap long-term savings on electricity bills.

This article covers these types of solar panels more in-depth and highlights solar panel design, materials, and efficiency ratings for each one to help you select the best solar panels for your home and budget.

While committing to the switch to solar can be easy, navigating the installation process can feel a bit overwhelming. Picking out panels alone requires some research and understanding of the science behind residential solar power.

Solar panels are made up of dozens of photovoltaic cells (also called PV cells) that absorb sunlight hitting a home’s rooftop and convert that energy into direct current (DC) electricity. Most home solar systems include an inverter, which changes the DC electricity to alternating current (AC) electricity that can then power the home. Battery backups can store unused solar energy for use at night or during an outage.

Though the brands and styles of solar panels are numerous, the good news is that there are just three main types of solar panels currently used in residential solar systems: monocrystalline, polycrystalline, and thin-film.

Monocrystalline solar panels—mono panels as solar companies often refer to them—are thus named because they are made from a single pure silicon. Monocrystalline panels are the most common ones found on rooftops in residential solar systems because they are the best-suited panel for small spaces and last longer than polycrystalline and thin-film panels.

There are two different kinds of monocrystalline panels: passivated emitter and rear contact (PERC) and bifacial. PERC panels have a conductive layer added to the backside of cells to increase energy absorption. PERC panels are most commonly used in rooftop solar systems.

Similarly, bifacial panels can absorb light on both sides but at a higher rate that PERC panels. For this reason, bifacial panels are typically reserved for ground-mounted systems that leave both sides of the panels exposed.

Monocrystalline Solar Panel Design

Monocrystalline panels are mostly solid black but have some white space throughout. The black design makes them less noticeable on a rooftop. However, they are not as sleek as thin-film panels, which are completely black and lay flat on roofs.

Monocrystalline Solar Panel Materials

Monocrystalline silicon solar cells are manufactured using the Czochralski method, in which a  seed crystal of silicon is placed into a molten vat of pure silicon at a high temperature. That creates a single silicon crystal, or ingot, that then is divided into thinner wafers. Those wafers make up the solar panels.

Polycrystalline panels represent earlier solar panel technology and therefore can be more affordable than the newer monocrystalline variety. However, because the technology is older, polycrystalline panels are not as efficient as their more modern counterpart. They also do not hold up well under high temperatures, so are not recommended for use in hotter year-round climates.

Polycrystalline Solar Panel Design

Polycrystalline panels have a blue hue due to their manufacturing process. The blue color is actually somewhat marbled in appearance, so there are some variations in color and consistency from panel to panel. Homeowners concerned with creating a subtle solar panel system should opt for monocrystalline panels over polycrystalline varieties.

Polycrystalline Solar Panel Materials

Polycrystalline panels are made of silicon solar cells, the same as monocrystalline panels. The difference is in the cooling process for polycrystalline panels, which creates multiple crystals rather than just one.

Polycrystalline panels used in home solar systems typically have 60 solar cells, which produces about 240 to 300 watts of power. The average residential solar panel, by comparison, contains 72 cells and generates 300 to 400 watts of electricity.

Due to their lower efficiency, thin-film solar cells are more often used in large industrial solar installations in which space is not a constraint. Conversely, thin-film panels can be a good option for smaller solar projects, such as in powering a boat, and smaller commercial buildings, like warehouses, with thin metal roofs.

Thin-Film Solar Panel Design

Thin-film panels have the sleekest appearance among the three-panel types. Because they are completely black, flat, and flexible in shape and size, they blend easily onto a home’s rooftop and do not require the scaffolding construction that monocrystalline and polycrystalline panels often do.

However, thin-film panels are not efficient, so you would need many more—perhaps even enough to cover your entire rooftop—to generate power for a home. That could result in higher overall costs and increased instances of panel issues, failures, and overall degradation over time.

Thin-Film Solar Panel Materials

A thin layer of a photovoltaic substance such as Amorphous silicon or cadmium telluride is placed onto a solid surface, often glass, to create a thin-film panel. The choice of photovoltaic substance used in the manufacturing process will create different thin-film panels, including some that are highly flexible.

Compare the Major Types of Solar Panels

If you’re looking for more information on how solar panels work, the video below describes the process of how solar panels converting solar power into energy and support your home’s electricity, heating, and cooling:

From a per-panel perspective, monocrystalline panels are the most efficient and therefore most expensive. Polycrystalline panels can actually be made by utilizing crystal fragments leftover from monocrystalline panel production. Since production costs are lower and the manufacturing process is simpler, polycrystalline panels are much less expensive than monocrystalline panels. Thin-film panels tend to be the cheapest type of solar panel overall because of their ultra-light and thin construction.

The following is the average cost per watt for each panel type, which is important to factor in when determining what you can expect to pay for your solar panels.

Average Cost Per Watt

• Thin-film: $.43–$.70
• Monocrystalline: $.32–$1.50
• Polycrystalline: $.70–$1.50

Get your Solar quote today.

The more electricity a solar panel can generate, the higher the efficiency rating. This also means that the most efficient panels will take up the least amount of space and fewer will be required for a functioning home solar system.

Efficiency is impacted by changes in sunlight throughout the day since overcast skies will obviously reduce the amount of solar energy panels can absorb. High heat levels can also negatively impact energy efficiency. Panels build up heat throughout the day and this can lower the power output by up to 25% during those times.

Both monocrystalline and polycrystalline panels are suitable for most locations that receive an average amount of sunlight and have seasonal temperature fluctuations. Thin-film panels have a lower temperature coefficient than the other two panel types, so they could be a good option for people who live in hotter climates or areas that get more annual sunlight.

While these slight variations affect all common types of panels, the highest efficiency varieties account for fluctuations and compensate for them in terms of overall power output.

Below is a breakdown of efficiency ratings and power capacity of each of the different types of solar panels.

Monocrystalline Panels

• Efficiency—over 20%
• Power capacity—up to 300 watts

Polycrystalline Panels

• Efficiency—15–17%
• Power capacity—240–300 watts

Thin-film Panels

• Efficiency—6–15%
• Power capacity—no standard measure, since thin-film panels aren’t uniform in size, but generally less output than crystalline panels

Factors to Consider When Selecting A Panel Type

Beyond sunlight exposure and heat, there are several other factors that can impact a solar panel’s performance.

Hail Rating

Solar panels are tested for hail impacts by dropping small steel spheres from a certain height or firing ice balls directly on panels to simulate hail.

Monocrystalline and polycrystalline panels are made of thicker materials and can therefore withstand hail hitting at speeds of up to 50 miles per hour. Thin-film solar panels, on the other hand, are less able to withstand hail because they are more lightweight and flexible.

Hurricane Rating

The U.S. Department of Energy maintains a list of recommended specifications for solar panels in terms of their ability to withstand major storms like hurricanes. Panels that meet these specifications will be designed with a locking or fastening mechanism to help prevent them from becoming windborne. Again, monocrystalline and polycrystalline panels, by their construction, are heavier and more able to be modified with fastening devices than thin-film panels.

For most residential solar systems, monocrystalline solar panels are the best option. While they are more expensive than polycrystalline panels, monocrystalline panels are higher-performing and longer-lasting. This means that despite the higher cost, the increased efficiency and power output from monocrystalline panels may actually save you money over time in terms of electricity bills.

However, polycrystalline panels are still a practical option for those who want to switch to solar but cannot afford the cost of monocrystalline panels. Keep in mind that if aesthetics is important to you, polycrystalline panels are the most noticeable and perhaps, outdated, of the three types of solar panels.

We do not recommend the use of thin-film panels in your residential solar system due to their inefficiency and long-term durability deficiencies. However, if you want to power a shed, workshop, boat, or recreational vehicle, thin-film panels may be a cost-effective option in a subtle design.

Understanding the differences in solar panel types—not to mention, the options available by brand—can be overwhelming. Most solar panel installation companies will recommend a panel type and brand based on your home’s needs and your budget. We recommend contacting Momentum Solar for assistance with your residential solar system design and solar panel selection.

To share feedback or ask a question about this article, send a note to our Reviews team at reviews@thisoldhousereviews.com.