So, you’ve read up on the best solar panels available and have decided to prioritize efficiency. Smart move. Buying the most efficient solar panels provides you with the most bang for your buck when working with limited roof space and is often (but not always) the best choice for homeowners.
In its simplest terms, solar panel efficiency refers to the amount of sunlight that falls on the panels that is converted into energy, or solar power. In this article, we’ll break down what makes solar efficiency important and help you pinpoint the most efficient solar panels for your home.
If you’re ready to seek out a certified solar installer in your area, you can use this tool or fill out the form below to get connected and receive a free quote.
Understanding the Efficiency of Solar Panels
Efficiency measures the amount of electricity a solar panel produces relative to the amount of sunlight (or irradiation) that strikes its surface. The most efficient solar panels on the market today only reach about 22.8% (shoutout to SunPower) — meaning that the panel converts about 22.8% of the sun’s irradiance into usable AC electricity.
This may sound like a small amount, but the rapid progress of solar technology has surpassed most expectations. Only about 10 years ago, solar panels averaged around 15% efficiency. The first solar panels from the mid-1950s only reached an efficiency of 2%. There are currently panels in development reaching efficiency levels nearing 50% that we may see hit the market sometime in the future.
Tracking Solar Panel EfficiencyData Credit: National Renewable Energy Laboratory (NREL)
What Are the Most Efficient Solar Panels Available Today?
With so many recent advancements in solar technology, let’s take a look at the most efficient solar panels available in 2022. Based on our research, these are the best solar panels for efficiency at the time of publication:
Most Efficient Solar Panels
SunPower Maxeon M-Series
LG NeON R
Jinko Solar Tiger Neo
REC Solar Alpha
Trina Solar Vertex S
FuturaSun FU M Zebra
LONGi Solar Hi-MO 5
Q Cells Q.Peak DUO G9+
Power refers to the wattage output capacity of the panel. The more powerful the panel, the more electricity it is able to produce. Note that power works in conjunction with efficiency, rather than determining it.
What Determines Solar Panel Efficiency?
Two main factors determine solar panel efficiency: the makeup of the photovoltaic (PV) cell, and the structure of the panel. You might wonder what differentiates the two.
Solar Cell Efficiency
A solar cell is the smallest unit within a solar panel, usually composed of silicon atoms. The photovoltaic effect — which is the process by which sunlight is turned into electricity — happens in the solar cells themselves, and solar panels join together multiple cells to produce higher amounts of power and allow that power to flow through a home.
Solar cells on a solar panelvisdia / Getty Images
The most efficient types of solar panels are usually monocrystalline (rather than polycrystalline or thin-film). In this type of panel, the solar cell is cut from one solid silicon crystal. This leads to fewer imperfections in the cell, making them more capable of absorbing sunlight and, thus, more efficient.
It’s possible you’ve heard about N-type or P-type solar cells in your research as well. This won’t matter very much to the average customer, but if you’re curious, these solar cell types differ in their chemistry due to the number of electrons they carry. N-type cells are negatively charged (via phosphorus), while P-type cells are positively charged (via boron). Multi-junction solar cells exist, too, made with both P- and N-type materials.
Solar Panel Efficiency
Overall solar panel efficiency has more to do with the structure of the panel itself. Even if you have the most efficient solar cells available, the next step is to gather those electrons and direct a current in a specific direction. A solar panel has to be as smoothly interconnected as possible, so as not to lose any energy in this part of the process. Temperature, cell type and design will have a large effect on overall efficiency in this context.
Why Is Solar Panel Efficiency Important?
It would be unfair to equate the most efficient solar panels with the best solar panels, as a number of other factors — namely durability, cost, warranty and power — can have a large impact on overall quality.
However, in residential solar, efficiency is typically one of the more important considerations. Here’s why.
Quicker Payback Period
The more efficient your solar power system, the higher your power output will be, and the more quickly you’ll recoup your initial investment. The cost of solar panels can be intimidating, but efficient panels will help slash a larger portion of your electricity bills, accelerating your solar payback period.
Something else to keep in mind is that the more efficient your solar panels are, the lower number of solar panels and inverters you’ll need to achieve your home energy goals.
Better for Limited Space
Many residential solar energy projects are confined in terms of space available for solar panels. Some might see their roofs and think there’s plenty of space, but zoning laws and regulations often require spaces between panels and gaps between the arrays and the sides of the roof. For homes with less roof space, high-efficiency panels allow you to do more with less.
In commercial solar installations where you have more space to work with, efficiency won’t be as big a factor.
Doing More With Less
In addition to working with limited space, requiring fewer solar panels lowers the impact of your solar project itself. As Dr. Yifeng Chen, head of efficiency research and development at Trina Solar, says, “improving module efficiency is a key to helping customers save land, labor, cables, etc.”
The highest-efficiency solar panels require fewer materials, shipping costs and waste. It may not seem like much to shave off one or two panels from your solar array, but seeing as the U.S. averages some 3 million solar installations per quarter, the impact can add up.
Other Factors Impacting Efficiency
At the risk of getting too technical, here are a number of other aspects of solar panels that factor into efficiency.
The spectrum of light that a solar cell is able to absorb can vary. Most modern solar cell technology is only capable of capturing visible light, excluding other wavelengths like infrared and UV rays. In general, the wider the spectrum of light that can be captured, the more efficient the cell will be. Some researchers are currently focusing on solar cells capable of capturing infrared rays, which would dramatically increase efficiency.
High temperatures and extreme weather conditions can put a lot of stress on a solar panel. In fact, solar panels are actually more effective in colder conditions when they can work without overheating. Panels that are durable, and that can withstand high temperatures, will have greater overall efficiency and lifespan.
Solar panels need a protective coating on them to ensure their longevity. What’s challenging, however, is that this protective coating shouldn’t reflect any of the potential energy the solar cells are trying to capture. Higher-efficiency panels will have high-quality protective coatings that reflect the least light possible, increasing overall energy production.
Environmental Factors Affecting Efficiency
While solar panel efficiency is determined in large part by solar cell technology and the construction of the panels themselves, there are also a number of other real-world contributors to the overall amount of power your system will be able to generate.
Climate and Latitude
Climate and latitude have a large impact on the overall efficiency of your solar energy system. The closer you live to the equator, the more direct sunlight you’ll receive on an annual basis. Climate factors in as well. If you live somewhere rainy or often covered by clouds, you won’t get as much production out of your system.
Solar Panel Orientation
Similar to the role of latitude, your panel orientation will affect efficiency. If you live in the northern hemisphere, the best direction for your solar panels to face is south (and north if you’re in the southern hemisphere), as this is how they will get the most direct sunlight. If your roof isn’t at a great angle for solar, your system will be less efficient.
Dirt, Dust or Grime Buildup
This factor is particularly unappreciated — you might be surprised how much production you lose when you don’t clean your panels. Fortunately, it’s pretty easy to give your panels the routine maintenance they deserve to keep your home powered on clean energy.
How to Find the Most Efficient Solar Panels
Solar panel manufacturers continue to make large strides in solar panel efficiency as the industry continues to recognize its value. Highly efficient, monocrystalline panels are ideal for residential solar systems, as those projects typically have the least amount of space to work with. For this reason, most top solar companies should be certified to sell and install the most efficient solar panels listed above.
If you’re looking to invest in high-efficiency panels, we recommend getting in touch with solar installers near you to inquire about their product portfolios. Now that you know so much about solar efficiency and why it matters, you’ll be well prepared to find the proposal with the best value for your money.
To start getting in touch with certified local installers, you can use this tool or fill out the form below.
FAQ: Most Efficient Solar Panels
What is the most efficient solar panel?
As of publication, SunPower’s M-Series panels hold the throne for the most efficient solar panels on the market, at 22.8% efficiency. Though there are more efficient solar panels in development, it will be some time before they’re available commercially.
Can solar panels be 100% efficient?
“In science, nothing is ever 100%.” — Michio Kaku
For a common solar panel to be 100% efficient, it would have to convert all potential energy that strikes its surface area into AC electricity. This means a solar panel would need to absorb no heat, cover every spectrum of light, not reflect any light, and not lose a single electron over decades of complex chemical processes.
However, there is research being done on what’s called “multiple exciton generation” (MEG). Researchers claim solar cells have surpassed 100% efficiency using MEG, a process by which “a single high energy photon can produce more than one electron-hole pair per absorbed photon. The extra efficiency comes from quantum dots ‘harvesting’ energy that would otherwise be lost as heat.” So, 100% efficiency may be attainable if we think outside the box.
Which solar panels produce the most electricity?
Another way to phrase this might be, “which solar panels are the most powerful?” This is measured by wattage. This past year was a landmark year for the power of solar panels, as some commercial and industrial panels from brands like Jinko and Trina are nearing 700 W.
Karsten Neumeister is a writer and renewable energy specialist with a background in writing and the humanities. Before joining EcoWatch, Karsten worked in the energy sector of New Orleans, focusing on renewable energy policy and technology. A lover of music and the outdoors, Karsten might be found rock climbing, canoeing or writing songs when away from the workplace.
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