Monocrystalline vs. polycrystalline solar panels
Exploring the differences between the two most common panel types
There are two leading types of solar panel technologies in use today: monocrystalline and polycrystalline. Commonly referred to as “mono” and “poly” for short, monocrystalline and polycrystalline solar panels are very similar in both name and nature.
Monocrystalline and polycrystalline panels, which make up roughly 95% of the photovoltaic (PV) energy market, both generate solar power using silicon, which is the second most abundant element in the Earth’s crust (behind oxygen). Monocrystalline panels are more more expensive but more efficient, which means they're ideal for residential installations where space is limited, while polycrystalline panels are more often used when space is less of an issue.
When you’re evaluating your solar panel choices, understanding the subtle differences between monocrystalline and polycrystalline technologies is important — you want to make sure to maximize your renewable energy investment.
Key insights
- Monocrystalline solar panels appear black; polycrystalline solar panels appear blue.
- Monocrystalline panels are more efficient and more expensive to manufacture.
- Poly panels work best at scale, while mono panels are more suitable for residential rooftop installations.
How solar panels work
It’s important to understand how solar panels work before going solar. We’ll break it down into four simple steps:
- PV solar panels are installed in a position and angle to receive as much direct sunlight as possible.
- When sunlight hits the surface of a panel, the energy is absorbed into its PV solar cells, which contain silicon wafer semiconductors.
- Within each PV cell, photons from the sunlight then “knock free” electrons in the silicon to generate a direct electric current (DC).
- The direct current is then passed through an inverter system to convert it into alternating current (AC) so the power can be safely used within a home or sent to the energy grid.
While monocrystalline and polycrystalline solar panels both follow these four main steps to operate, the key difference between the technologies lies within the different forms of silicon inside the PV cells.
What are monocrystalline solar panels?
“Mono” means “one” or “singular,” and the term monocrystalline refers to the single crystals of silicon that can be found in these PV cells. Rather than using materials from various silicon fragments, monocrystalline solar panels are made up of “pure” wafers that are sourced from singular silicon crystals.
Generally considered the more capable technology, monocrystalline solar panels are favored by many solar companies for their installations. In addition to their benefit of having more “pure” solar cells, monocrystalline panels are usually dark, black and sleek in appearance, making them less aesthetically intrusive than other PV arrays.
In a review on our site, John from Davis, California, said about their mono panels: “The panels look great on my roof. I went with the all black panels, and I could not be happier.”
What are polycrystalline solar panels?
Lighter in hue than their monocrystalline counterparts, polycrystalline (also known as many-crystal or multicrystal) panels have the shimmering blue color most people associate with solar energy installations.
Poly (meaning “many” or “multiple”) panels are developed using fragments from several different silicon crystals rather than a single cohesive piece. To create a polycrystalline solar panel, the silicon fragments are melted together to form the wafers that are found inside each poly PV cell.
Monocrystalline vs. polycrystalline: What’s the difference?
Mono and poly panels share several qualities, but their differences are notable. There are a few practical elements to consider when choosing.
| Monocrystalline | Polycrystalline | |
|---|---|---|
| Appearance | Black solar cells | Blue solar cells |
| Cost | More expensive | Lower costs to produce |
| Efficiency | More efficient | Less efficient |
| Required Space | Less installation space required | More suitable for large areas |
| Performance | Slightly larger temperature rating | Limited performance in extreme temperatures |
| Materials | Pure, single silicon crystals | Various silicon fragments melted together |
| Life span | 25 years or more | 25 years or more |
Appearance
In general, people tend to favor the appearance of monocrystalline solar panels; the black PV cells are less noticeable on darker-colored roofs. While blue polycrystalline panels are typically detailed with silver lines and an aluminum frame around the cells, some monocrystalline manufacturers keep dark colors consistent throughout their product designs.
Cost
When you’re trying to determine how much solar panels cost to install on your property, it’s important to understand that monocrystalline equipment comes at a premium price. Although choosing between mono and poly solar panels may not affect other aspects of your total installation costs, the price for the pure silicon crystals is pretty much guaranteed to raise your material expenses.
Efficiency
Most commercial solar panels have an efficiency between 15% and 20%, meaning they can convert roughly a fifth of the sun’s energy into usable electricity. While polycrystalline solar cells tend to be on the low side of this scale, monocrystalline panels have been tested to generate electricity at efficiencies of 24% and higher.
Performance
When harnessing the sun all year long, monocrystalline solar panels can generally better handle extreme conditions with less intrusive results. According to the American Solar Energy Society, polycrystalline solar panels have a higher temperature coefficient than monocrystalline panels. This means poly panels are more likely to lose efficiency in very hot or cold conditions, which could lead to permanent damage.
Space
Monocrystalline solar panels are more efficient and can generate more electricity than a set of polycrystalline modules while covering the same amount of space. This means monocrystalline panels are better for installations where space is limited, such as a residential roof or a small backyard.
At scale, large solar farms can save on material costs without sacrificing total power output by installing polycrystalline panels over a greater land area.
Materials
The defining distinction between mono and poly panels can be found at the silicon level. Plain and simple, monocrystalline solar panels are made using a more pure and uniform material than polycrystalline modules, which makes them more difficult and costly to produce.
Life span
Although some studies have shown mono cells to have longer operating life spans, the overall life of polycrystalline and monocrystalline solar panels is largely the same. You can expect both mono and poly solar panels to last for 25 years, with the majority of both products containing recyclable materials.
How to choose between mono and poly panels
If you’re deciding whether or not solar is worth it, evaluating both monocrystalline and polycrystalline options can be helpful to understand both the price and performance you can expect from your PV installation.
While every project is unique, homeowners looking to maximize limited roof or property space usually find that the extra-efficient production of monocrystalline solar panels tends to make the most sense for residential installations.
In general, most residential panels are monocrystalline, and most commercial or grid-level installations are polycrystalline.”
On the other hand, shared solar farms and large-scale projects may have the luxury of investing in slightly less expensive equipment to produce the same results. With a large enough installation area, the extra material costs for monocrystalline solar panels may not be worth it when an installation could utilize polycrystalline panels just the same.
“In general, most residential panels are monocrystalline, and most commercial or grid-level installations are polycrystalline,” according to John Striebel, the CEO of Apollo Energy, a solar installer based in Denver.
Solar can be helpful in a wide variety of applications, and choosing between monocrystalline and polycrystalline panels may not be the last step for every installation. New technologies like solar shingles and other building-integrated photovoltaics (like solar windows and skylights) are bringing mono and poly solar cells into many interesting forms.
As an alternative to traditional, bulky rigid panels, there are also several thin-film and flexible solar collectors you can choose from today. While rigid panels are strongly recommended for residential use, those looking for a mobile solar solution in an RV, camper van or boat can consider flexible solar panels with both polycrystalline and monocrystalline capabilities.
Bottom line
At the end of the day, finding the perfect panels usually begins by working with a top-tier solar energy company. While most installers tend to source their own equipment, deciding between monocrystalline and polycrystalline solar panels isn’t always up to you as a home or business owner; rather, it’s in the hands of local solar experts.
With this in mind, recognizing that monocrystalline solar panels will both look and perform better on your roof is a great first step when vetting installers and finding the right company for your installation.
Article sources
- U.S. Department of Energy, “ PV Cells 101: A Primer on the Solar Photovoltaic Cell .” Accessed Feb. 7, 2023.
- American Solar Energy Society, “ Monocrystalline vs Polycrystalline Solar Panels .” Accessed Feb. 7, 2023.
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