Most Efficient Solar Panels for 2024: US Customers Still Waiting on Record-Setting Panel - CNET

Oct 15, 2024

The latest in rooftop solar panel technology is nearly 25% efficient. But does having the most efficient panel really make a difference?

The most efficient residential solar panel right now is the Maxeon 7, which dethroned the older Maxeon and Canadian Solar panels when it launched in February 2024. Maxeon has consistently remained ahead of its peers in the industry when it comes to solar panel efficiency for some time, and its newest offering had its record-setting efficiency metrics confirmed by the National Renewable Energy Laboratory. The 24.9% efficiency mark recorded in lab settings translates to about 24.1% in more realistic settings -- essentially, what'd be recorded if they were on your rooftop. There's one catch for American solar shoppers: The Maxeon 7 won't be available in the US market until the first quarter of 2025, which means that it won't be part of any rooftop solar system you might be installing right now.

While nearly 25% is an eye-catching number, experts have told us that fixating on efficiency isn't always the way to go, especially for someone looking into a residential installation. You'll want to consider the whole output of a solar panel system and its total cost, not just the specs of an individual panel. Small jumps in efficiency might not be worth major leaps in your project costs, especially considering your price will be multiplying based on your solar panel system size. And you may not want to wait for better or cheaper options, although solar tech keeps improving and installation costs are trending down. Still, if you have limited space -- such as a small roof or a lot of shading -- highly efficient panels could make sense. Maxeon 7 aside, here are the solar panels that perform the best.

Solar panels may all seem basically the same, but they're different in at least a few key ways. One of those ways is the efficiency rating, which measures how much of the sun's energy a panel's solar cells turn into usable electricity. More efficient solar panels will generate more electricity than less efficient ones given the same amount of sunlight. Getting more electricity from the same amount of sunshine means you can further tamp down some of your energy costs over time.

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"If something is 20% efficient, that means that 20% of the energy in that sunlight reaching the solar panel gets turned into moving electrons," Daniel Ciolkosz, professor of agricultural and biological engineering at Pennsylvania State University, told CNET.

The 20% efficiency of some panels is much different than the nearly 25% efficiency of the Maxeon 7, for example. That means an extra 5% of the energy from the sunlight hitting the panel is getting turned into moving electrons -- producing electricity.

Choosing the best solar panels for your home is a game of balancing solar panel cost, function (like efficiency) and perhaps even aesthetics, if that's a variable that matters to you. Your choice is also limited by what solar equipment your chosen installer actually has available.

I've read dozens of spec sheets and talked to numerous industry experts about what matters for home installations. While ranking panels by their efficiency rating is a relatively straightforward task, I've also created the scoring methodology for the best solar panels and ranked them.

This list ranks the most efficient solar panels as identified by our mid-April 2024 survey of the specifications solar companies have publicly available. We'll tell you which panels get top marks for turning sunlight into the most energy, and we'll explain how much solar panel efficiency actually matters when it comes to residential rooftop solar.

Maxeon's newest residential panel is also its most efficient. It beats its nearest competitors by one full percentage point. It also has a temperature coefficient of -0.27%, which means it won't slow down as much as others as temperatures rise. Maxeon also extends one of the strongest production guarantees, saying that its panels will still produce at 92% capacity after 25 years.

Canadian Solar's 470-watt model of its HiKu6 panel is the largest panel by watts on this list. (As models of the same panel series get larger, they get more efficient.) The HiKu6's temperature coefficient of -0.29% and its 25-year guarantee of 89.4% of its production both come up just short of Maxeon's best marks.

Maxeon has sold its panels in the United States through SunPower and its subsidiary Blue Raven, though it could start selling through more installers after an exclusive relationship ended in March. The Maxeon 6's efficiency mark matches what used to be the top mark. Its temperature coefficient and production warranty match those of the Maxeon 7.

Maxeon's third entry on the list has an energy coefficient of -0.27% and a maximum 25-year degradation of 8%.

At -0.24%, REC's Alpha Pure panel has the best temperature coefficient. It will lose less production at higher temperatures than other panels. Larger versions of specific solar panels are more efficient than smaller ones, and this is one of the largest panels on our list. It's guaranteed to produce at 92% of its original capacity after 25 years.

Qcells has been the most widely installed residential solar panel brand in the United States. This is their most efficient residential panel to date. It has a temperature coefficient of -0.3% and a 25-year production guarantee of 90.58%.

The Tiger Neo panel has a 22.52% maximum efficiency rating and a temperature coefficient of -0.29%. After 30 years Jinko guarantees the panel will produce 86.54%

Determining the highest solar panel efficiency is a pretty simple matter of tracking down manufacturer-provided data sheets and locating the efficiency numbers. Those numbers today are higher than in the not-too-distant past and keep creeping upward.

According to the Lawrence Berkeley National Laboratory's Tracking the Sun report, 2021 was the first year more than half the residential solar panels installed in the US had efficiency ratings above 20%. Ten years ago only 0.6% of those installed reached that mark.

If you're looking for the most efficient solar panel for your roof, here's how the most widely used brands on the market stack up.

Data collected in April 2024.

It depends on the solar panel. The most efficient solar panel on our list tops 24%, meaning they convert more than 24% of the available energy from sunlight into usable electricity. Not all solar panels hit that figure, and the ones you buy might fall below it. Be sure to examine not just efficiency, but the whole expected output of your solar panel system for the price.

These are just the most efficient residential solar panels. Experimental technology and panels designed for commercial and utility-scale applications can be even more efficient.

The numbers listed above are obtained under controlled conditions in laboratory tests. In the real world, plenty of factors might cause you to receive less energy than a panel's efficiency rating would suggest.

Sunlight: If the skies are hazy or cloudy, less sunlight will reach your panels and they'll produce less electricity than expected.

Solar panel angle: Solar panels will work facing in most directions, but there's an optimal angle and placement for your panels that depends largely on where you live.

Other electrical components: Power doesn't flow straight from the panels into your toaster. Some will be lost along the way through the inverter and other electrical devices.

Temperature: Another factor affecting solar panels' efficiency is their temperature. As solar panels get hot, they start to produce less energy, though not at the same rate. A solar panel's temperature coefficient measures how much worse its production gets for every degree Celsius (1.8 degrees Fahrenheit) it gets above 25C (77F).

Solar panels are installed at an angle to capture more of the sun's energy.

For example, at 26C (79F) a REC Alpha Pure would produce 0.24% less energy than at 25 degrees. At 29C (84F), it would lose just shy of 1% of its production.

There are three main types of solar panels, and each converts sunlight into power at a different rate. Here's a look at the three types:

All things being equal, it would make sense to choose a higher-efficiency solar panel over one with a lower rating. High-efficiency solar panels typically cost more than lower-rated ones, so making the best choice becomes a matter of balancing your financial goals with what your preferred installer offers and other considerations like brand and aesthetics.

"It's just one part of the equation," said Ciolkosz. "The bigger question for the end user is the economics and how it's paying off."

Is there a case where efficiency might be a worthwhile consideration?

"If you have one of those tiny homes on HGTV," said Tom Beresnyak, a Pennsylvania State University extension educator.

If you're limited by available space for solar panels, you might want to squeeze out as much solar energy as possible from that space, although if your state allows it, a community solar subscription still might be a better choice financially, Beresnyak said.

No, but the panels listed here aren't the most efficient solar panels ever made -- just commercially available ones marketed for homes.

Research into solar cells (the energy-producing components that make up solar panels) has produced much higher efficiencies in the lab. The National Renewable Energy Laboratory tracks the highest efficiencies achieved in standardized lab conditions. The highest-ever solar cell efficiency was 47.6%, recorded in June 2022.

Because there's no one-size-fits-all solar setup, there's no one-size-fits-all advice for choosing a solar company. The best approach is to get quotes from multiple installers before deciding. You should be aiming for at least three to five quotes from different companies before contracting with anyone. Choose the company that has offered you the best fit for your needs, you trust to do the work and has answered all your questions.

You should understand your energy usage before going solar and decide whether your goals are to completely replace that energy, save as much money as possible or achieve something else. From there, it's a matter of measuring competing quotes against your goals.

The Department of Energy recommends that you choose an installer with credentials from a respected third party, like the North American Board of Certified Energy Practitioners, which operates an online directory of certified installers that you can filter by state and certification.

Installers should definitely assess your roof condition because removing panels at a later date to replace a roof will be an additional cost. They should also be able to transparently answer questions about the system's design and why they're making their specific proposal.

"The installer can make a huge difference because the angle and the mount [are important for] maximizing what you have at that location -- a skilled installer is still going to be the real key in your long term production," Beresnyak said.

Read more: See our picks for the best portable solar panels and solar backup generator.

The panels on this list were chosen because they're some of the most commonly installed panels and are likely to appear on quotes for solar installations. If you're quoted for panels that don't appear on this list, you can check their efficiency rating and other specifications in the same way I did. Here's how.

Solar panel manufacturers publish data sheets for solar panels, which detail their dimensions, performance metrics and internal chemistry. If your solar company doesn't provide you with them, you can access them by clicking on the company name in the table above. (Many of the links lead to PDFs.) From there, it's a simple matter of comparing statistics.

Most of the solar panels installed today are made of either monocrystalline or polycrystalline cells. Monocrystalline solar panels are more efficient than their polycrystalline counterparts, although they're a bit more expensive. They make up nearly 100% of residential panels installed today. All the solar panels listed above use monocrystalline cells.

A third type of solar panel, thin-film solar panels, are less efficient than mono- and polycrystalline panels.

At the moment, the most efficient solar panels available on the residential market are made by Maxeon. Other companies are catching up, and technology continues to improve.

In general, yes. While specific pricing information for solar panels isn't readily available, higher-performance panels are typically more expensive. SunPower, which installs the most efficient panels, also started installing Qcells panels (the most frequently installed panels) to offer a more affordable option.

That means the panel is converting 20% of the energy from the sunlight that hits it into electricity. Of residential solar panels currently available, 20% would rank favorably. The most efficient solar panels on the market are more than 22% efficient.

In the residential market, the most efficient solar panels come from Maxeon and are 24.1% efficient. Larger, utility-scale solar panels can be more efficient than residential panels and technology still in research phases has almost doubled that efficiency.

Article updated on October 11, 2024 at 11:14 AM PDT

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