The five most efficient residential solar panels in 2023.
If you’re shopping around for solar panels, you’ve probably come across the term “solar panel efficiency”. It’s on practically every solar manufacturer's website in bold font: “19% Efficiency!” or “Our highest efficiency solar panel!”
A solar panel's efficiency rating tells you how much of the sunlight that hits the panel is turned into usable electricity. The higher the efficiency rating, the more sunlight that panel can turn into electricity.
Solar panel efficiency has been increasing for decades. Today, most home solar panels have efficiency ratings between 19% and 21%. The most efficient solar panels can reach over 22%!
But, how efficiently your panels operate depends on more than just their rating. Let’s take a closer look at the most efficient panels for homeowners today, how much they cost, and what other factors impact efficiency.
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- Solar panel efficiency is a measure of how much of the sunlight that hits the surface of a solar panel is converted into electricity.
- Most solar panels today are between 19% and 21% efficient.
- SunPower, Canadian Solar, and REC Group all have efficiency ratings above 22%, making them the most efficient panels on the residential market today.
- The type of solar panel, the construction of the panel, and outdoor conditions all impact how efficiently a solar panel operates.
- The power output rating and the value of the solar panel you choose is more important than the efficiency rating.
What is solar panel efficiency?
The efficiency rating of a solar panel tells you what amount of sunlight that hits a solar panel is turned into usable electricity. The higher the efficiency rating, the more sunlight that panel can turn into electricity.
So, if a solar panel has a 15% efficiency rating, that means 15% of the solar energy within the sunlight that hits the solar panel will be converted into electricity.
You can get a more in-depth explanation of solar panel efficiency from SolarReviews founder Andy Sendy in this video:
How efficient are solar panels?
The median efficiency rating of residential solar panels installed from 2022 to 2021.
According to the National Renewable Energy Laboratory (NREL), most solar panels installed today have efficiency ratings between 19% and 21%. Solar panels with efficiency ratings close to the 22% mark are considered premium efficiency panels and are only offered by a few manufacturers like SunPower and REC Group.
That’s a long way from where we were in 1954 when the first silicon solar panels had efficiency ratings of just 6%. Just ten years ago, solar panels were only about 13.4% efficient! We could see even more improvements in efficiency thanks to exciting new advancements like perovskite solar cells, which have the potential to reach efficiency ratings of 50%!
The most efficient solar panels of 2023
The following table outlines the most efficient residential solar panels of 2023:
| # | Manufacturer | Model | Power Output |
Efficiency* |
|---|---|---|---|---|
| 1 | SunPower | M Series | 440 W | 22.80% |
| 2 | SunPower | X-Series | 370 W | 22.70% |
| 3 | Canadian Solar | HiHero | 440 W | 22.50% |
| 4 | REC Group | Alpha Pure | 410 W | 22.20% |
| 5 | Panasonic | EverVolt H | 410 W | 22.20% |
| 6 | Maxeon | Maxeon 3 | 420 W | 22.2% |
| 7 | Silfab | Elite | 410 W | 21.4% |
| 8 | LONGi | HiMO4M | 460 W | 21.20% |
SunPower has consistently held the number one spot when it comes to efficient ratings, but that could change in the near future. In 2020, SunPower’s manufacturing branch, Maxeon, spun off as its own company. SunPower’s most efficient panels are still manufactured by Maxeon. But in 2023, Maxeon solar panels are becoming available to installers outside SunPower’s network. The break-up could finally dethrone SunPower as the most efficient panel, but they’re still holding strong for now.
How much do high-efficiency solar panels cost?
You could spend a few thousand dollars extra for premium efficiency solar panels.
High-efficiency solar panels tend to come with a higher price tag and can add a premium of over $2,000 to the total cost of your system. So, a 7 kilowatt (kW) solar system using premium efficiency panels might cost around $23,100, while the same system using regular efficiency panels might be closer to $19,900.
But, the cost of highly efficient solar panels is getting lower, thanks to brands like Trina Solar and LONGi. These Chinese-based companies are making great-quality panels with excellent efficiency ratings for a fraction of the cost of premium brands like SunPower. As these brands develop more products, you could see efficiencies rise while solar panel costs remain the same.
What factors impact solar panel efficiency ratings?
Solar panels are manufactured like a layer cake. There's the front glass sheet, a layer of encapsulant, the solar cells, more encapsulant, a backsheet, and an aluminum frame holding it all together.
The materials used to make these layers play a major role in how efficiently a solar panel can turn sunlight into electricity. They include:
- Cell type
- Busbars and wiring
- Backing
Let’s take a closer look at each and how they impact the efficiency of a solar panel.
Solar cell type
One of the biggest determinants of solar panel efficiency is the type of solar cell used. Solar cells are the part of the solar panel that turns sunlight into electricity. There are three main types of silicon solar cells:
- Monocrystalline solar cells are the most efficient and the most commonly used solar cells for residential solar panels.
- Polycrystalline solar cells are less efficient, usually with ratings below 17%, and are rarely used for new home rooftop solar installations.
- Thin-film solar cells are the least efficient and typically aren’t used for home solar installations.
Monocrystalline solar panels are the most common type of solar panel used today because they perform better than other cell types. This hasn’t always been the case, though. Believe it or not, polycrystalline panels were once the most popular because they were substantially cheaper than the alternatives.
But, monocrystalline technology continued to improve while getting cheaper, making it the best choice for residential solar installations. The shift to monocrystalline panels is a big reason why average efficiency ratings have increased over the years.
Solar cell construction
As we said, most solar panels today use monocrystalline solar cells. But, there are different ways in which monocrystalline solar cells can be constructed to make them even more efficient. These include:
- PERC solar cells: Also called ‘passivated emitter and rear contact cells’, PERC cells typically provide about 1% in added efficiency thanks to a reflective back layer that reflects back any light that may have passed through the cell.
- HJT solar cells: Heterojunction with intrinsic thin layer cells are just traditional monocrystalline solar cells that have been sandwiched between layers of a different type of silicon that absorbs various wavelengths of light and increases power production. Panasonic and REC Group are known for using HJT solar technology.
- Half-cut or Split cells: Split-cell technology is exactly what it sounds like - solar cells are cut in half with a high-precision laser, which reduces heat and resistance, thereby increasing overall efficiency.
Busbars and wiring
How solar cells are wired together can also impact how efficiently they can generate electricity. If you look at the face of a solar panel, you’ll see a bunch of thin lines. These are a series of copper or aluminum wires that conduct electricity throughout the panel.
Some solar manufacturers have switched to multi-busbar technology, where multiple ultra-thin busbars are used instead of fewer, thicker busbars. The thinner busbars reduce the amount of shading on the solar cell and allow it to absorb more sunlight, thus increasing efficiency.
SunPower and Silfab use interdigitated back contact, or IBC cells, where all busbars and wiring are on the backside of the solar cell. This frees up the entire face of the cell to absorb electricity without shading issues. However, IBC cells are complicated and expensive to manufacture.
Backing
If you’ve ever looked at a traditional solar panel, you’ve probably seen the black solar cells surrounded by some white space. That white space is the panel’s backsheet. You may also have seen some all-black solar panels; these panels might have a black backsheet.
Black backing is popular among homeowners because it gives the panels a sleek, uniform look by blending seamlessly with the color of the solar cells. However, panels with black backing are slightly less efficient than those with white backing because it makes the solar panels hotter. Believe it or not, as the surface of a solar panel gets hotter, its efficiency decreases.
Do environmental conditions affect a solar panel’s efficiency?
Everything we’ve talked about so far is specifically talking about a solar panel’s efficiency rating. The efficiency rating is calculated under a standard set of laboratory testing conditions, and unfortunately, solar panels on your roof won’t be getting these ideal settings.
This means how efficiently your panel will actually be will vary, depending on many factors, including:
- Temperature: As the surface of a solar panel gets hotter, its efficiency drops. Solar panels actually operate best in cold but sunny conditions.
- Solar system orientation: In the U.S., solar panels produce electricity most efficiently on roofs facing south. Solar panels facing other directions will get less sunlight, which decreases how efficiently the panel operates.
- Solar system angle: The ideal angle for solar panels is between 30° and 45°, depending on where you live. If your roof has a very steep or shallow pitch, it might decrease the amount of electricity that solar panels can produce.
- Shading: Solar panels work best in direct sunlight. If a solar panel experiences any shading, like the shadow from a tree branch, it won’t produce as much electricity.
- Weather: Solar panels operate best on clear, sunny days. Even a passing cloud can impact how much electricity the panels generate. Snow accumulation can prevent energy production altogether, so you might need to clear them off if you get a lot of snow.
- Debris: If you live somewhere that is particularly dusty, or maybe in a place that experiences regular wildfires, debris may accumulate on your solar panels and reduce the amount of sunlight they can turn into electricity. Even something as small as bird poop can cause a drop in solar production. Most often, rain storms will take care of removing anything on your panels, but you may need to consider cleaning them off to maximize electricity production. Most often, rain storms will take care of removing build-up, but you may need to consider cleaning your panels to maximize electricity production.
How is solar panel efficiency calculated?
When you’re shopping for solar panels, the efficiency rating will be listed on the panel’s datasheet. But how exactly is it calculated? There’s actually a pretty easy formula for calculating solar panel efficiency:
Efficiency = [Power output of panel / (Area of panel x solar irradiance)] x 100
When solar panels are tested in the lab under Standard Test Conditions (STC), it’s assumed they will receive irradiance levels of 1,000 watts of sunlight per square meter. Knowing this, let’s calculate the efficiency rating for a:
350-watt panel with an area of 1.8 square meters:
Efficiency rating = [350 watts / (1.8 m2 x 1,000 watts per m2)] x 100
Efficiency rating = 19.4%
So, this 350-watt panel has an efficiency rating of 19.4%. Not bad!
Do you really need high efficiency solar panels?
We’re going to be totally honest with you; a panel's efficiency rating is not the most important thing to consider. In fact, our top pick for the best solar panel manufacturer of 2023 doesn’t have the highest efficiency panels on the market.
You can learn more about this from veteran solar expert Will White:
What you should focus on is the power rating of the panel and the reliability of the brand you’re using. The powering rating tells you how much electricity a solar panel can produce, which considers the panel's efficiency.
You also want to consider the brand’s reliability. You want to get solar panels from a company that produces high-quality products that can support you over the 25-year lifespan of the panels, should you need it.
However, high-efficiency panels may be useful if you have a small roof. Panels with higher efficiencies can produce more power in a smaller area, allowing you to maximize your roof space.
Learn more: How many solar panels do I need to run my house?
The following table lists some alternatives to expensive high-efficiency solar panels:
| Manufacturer | Model series | Output | Efficiency |
|---|---|---|---|
| Qcells | Q.Peak DUO Black MK | 410 W | 20.90% |
| Jinko Solar | Eagle 66-TR G4 | 400 W | 20.96% |
| Trina Solar | Vertex S 395 W | 395 W | 20.80% |
| Mission Solar | MSE PERC 66 | 400 W | 19.9% |
| JA Solar | 60-Cell MBB Half-Cell Module | 390 W | 21% |
Are premium efficiency solar panels right for you?
Premium efficiency solar panels are the best choice for homeowners with limited roofing space or those who don’t mind spending extra money on top-of-the-line products.
But, for everyone else, you should consider what solar modules give you the best value for the price. Can you trust the manufacturer? Is the warranty good? You want a solar panel that’s reliable, high-quality, and meets your power needs without breaking the bank. Qcells, LONGi, and Canadian Solar are all great options.
To better understand how much solar panels can save you, check out our solar panel calculator. From there, you can contact local, reliable solar installers who can help you pick the best solar panel brand for your roof so you can start powering your home with cheap, clean energy.
Catherine Lane
Written Content Manager
Catherine is the Written Content Manager at SolarReviews. She has been researching and writing about the residential solar industry for four years. Her work has appeared in Solar Today Magazine and Solar Builder Magazine, and has been cited by publications like Forbes and Bloomberg.