There are two major types of solar panels: monocrystalline (“mono”) solar cells and polycrystalline (“poly”) solar cells. Both are manufactured using crystalline silicon and can reliably produce solar energy for your home.
But the two panel types also have some important differences. The primary difference between them is that poly panels are less efficient than mono panels. In other words, a poly panel that is the same size as a mono panel can capture and transmit less of the sun’s energy. While mono panels might have efficiency rates of 16 to 18 percent, poly panels tend to have efficiency rates of 13 to 16 percent on average.
The two types of cells also look different. While poly cells are perfectly rectangular and blue, mono cells are black and might have rounded or sliced-off corners.
Mono panels are more efficient because they’re made from a purer form of silicon than their polycrystalline counterparts. As their name suggests, monocrystalline cells are cut from a single crystal (or “boule”) of silicon. They have a more uniform appearance than polycrystalline cells, which are cut from a piece of silicon that was melted and recrystallized. These differences in the manufacturing process allow electrons to move through the mono cell more easily than they can through the poly cell, which results in different levels of efficiency.
However, mono panels are also more expensive to produce, so for panels of any given wattage, you’ll likely pay more for mono panels. Some of SunPower’s high-efficiency monocrystalline panels, for instance, can reach efficiencies of over 22 percent. SunPower panels use cells that are free of the metal paste that traditional solar cells have on their front side. Removing this paste allows more sunlight to reach the cell, thus increasing efficiency. The cells also have a solid copper backing that makes them less susceptible to corrosion and improves the cell’s ability to withstand temperature fluctuations. But this premium quality will cost you anywhere from $3.65 to $4.55 per watt, including installation. The average installed price of solar panels, by contrast, is $3.16 to $4.26 per watt.
Premium mono panels from LG Energy－like the NeON R or NeON 2－are also highly rated. Some LG panels exceed 23 percent efficiency. In the Neon 2, LG uses Cello technology to replace the busbars－the thick metal strips that bind one solar cell to another－with thin wires. By eliminating busbars, LG cells achieve the same effect that SunPower cells do, exposing more of the cell surface to sunlight and thus improving overall cell efficiency. In the NeON R, all electrodes are mounted on the rear of the cell, allowing for maximum absorption of sunlight. Expect to pay around $3.08 to $3.98 per watt for LG’s premium panels. LG panels with lower efficiency rates (16.8 to 19.5 percent) cost somewhat less, hovering around $3.30 to $3.67 per watt.
Panasonic’s high-efficiency mono panels also come with a premium pricetag of around $3.37 to $3.86 per watt. In addition to a monocrystalline silicon wafer, Panasonic uses two amorphous silicon layers (one on either side of the mono cell) to improve performance. Panasonic panels can achieve efficiency rates greater than 19 percent.
Other monocrystalline makes and models include:
Monocrystalline panel efficiencies
|LG Energy||335-watt NeON 2||19.6 percent|
|LG Energy||320-watt NeON 2 Black||18.7 percent|
|LG Energy||315-watt NeON 2 Black||18.4 percent|
|SolarWorld||300-watt panel||17.9 percent|
|Hanwha Q CELLS||300-watt Q.PEAK||17.1 percent|
|Astronergy||330-watt panel||17.1 percent|
|Astronergy||275-watt panel||16.9 percent|
|Boviet Solar||270-watt panel||16.6 percent|
|S-Engery||270-watt panel||16.5 percent|
|Sunerg||260-watt panel||16 percent|
So, which should you choose－the higher-efficiency monocrystalline panels or the standard-efficiency polycrystalline panels? If you’re low on roof space, mono panels are your best bet. Otherwise, don’t fall for the high efficiency trap. If you use less efficient panels, you might have to put more (or larger) panels on your roof, but you’ll be able to produce the same amount of electricity as you would with a higher-efficiency panel. Even if you end up adding additional panels, your standard-efficiency system will cost 10 to 20 percent less than a system composed of mono panels. To learn more about which solar panels are right for you, or talk to a solar installer, contact PowerScout today.