Skip to content
Solar Panel Efficiency: What Does It Really Mean. Solar pv efficiency

Solar Panel Efficiency: What Does It Really Mean. Solar pv efficiency

    Solar Panel Efficiency: What Does It Really Mean?

    When you review the technical specifications of solar panels, their efficiency values may give a negative first impression. As of 2021, monocrystalline solar panels are in the range of 20-23%, while polycrystalline panels are below 20%. However, conversion efficiency is not a critical factor when using sunlight. a free and virtually limitless resource.

    Save on electricity bills and cut building emissions with solar power.

    On the other hand, when the energy inputs for power generation are fossil fuels, efficiency becomes much more important. Coal power plants are typically 30-40% efficient, while combined cycle gas plants are around 50-60% efficient.

    • These generation systems have a higher efficiency than solar panels, but looking only at this metric can be misleading.
    • Solar panels are less efficient in terms of energy conversion, but their input is free and they operate with zero emissions.

    Solar panel efficiency is only an issue when space is limited, since you may not reach the planned capacity in kilowatts. The solar panels used in commercial and industrial roofs have typical dimensions of around 80” x 40”, and the most efficient models exceed 400W. If you want to install 400 kW, you need 1000. this represents more than 22,000 sq.ft. for the solar panels alone, plus the spacing required for maintenance purposes.

    What Determines Solar Panel Efficiency?

    The top solar manufacturers are constantly investing millions in research and development, with the goal of improving their photovoltaic cells. However, this has paid off over time:

    • Back in 1990, solar panels could only convert around 10% of sunlight into electricity.
    • As of 2021, the most efficient solar panels in the market are approaching 23% efficiency.
    • In other words, solar panels can now produce 2.3 times more energy with a given space, compared with how they performed 30 years ago.

    The efficiency of solar cells is determined by the photovoltaic material, and also how the module is wired and designed overall. Monocrystalline cells are more efficient, since they’re made of single silicon crystals of high purity. On the other hand, polycrystalline cells are made of multiple crystals, and this impacts their efficiency.

    This does not mean that polycrystalline solar panels have a lower quality. They have a lower conversion efficiency due to their material properties, but there are high-quality solar modules of both types.

    What Are PERC Solar Cells?

    Many of the top-performing panels that are currently available use PERC technology, which increases productivity by up to 12%. PERC stands for Passivated Emitter and Rear Contact, and these cells have many design features that boost their efficiency.

    • PERC cells have a reflective layer below them. sunlight that goes through is reflected back into the photovoltaic material, generating more power.
    • They also have anti-reflective coatings and surface textures that maximize the sunlight captured and converted into electricity.

    PERC cells are often cut in half to reduce their electrical resistance losses, further increasing their power output. You will notice that many solar panels are now using 120 or 144 half-cells, instead of the traditional 60-cell and 72-cell designs. Since solar cells are cut in half, their total space requirements are almost the same and panel dimensions are not affected significantly.

    How High-Efficiency Solar Panels Save Space

    As the efficiency of photovoltaic cells continues to increase, solar panels will be capable of generating more watts per square foot.

    • A 400W solar panel that measures 80” x 40” is producing 18W per sf.
    • With an efficiency increase of 33%, it would be possible to generate 24W per sf.

    Generally, having space for solar panels is not an issue in buildings like shopping malls and distribution centers. However, multi-story buildings have a large floor area relative to their roof area. and plenty of the available space is already used by HVAC equipment. In these cases, high-efficiency solar panels will maximize the kWh output per square foot covered.

    solar, panel, efficiency, does, really

    RD has also reduced the cost of solar panels. You could expect to pay more than 10,000 per kW of capacity 20 years ago, but now home solar systems cost less than 3,000 per kW in many parts of the US. Even lower are possible in the utility sector, where solar arrays are being installed for less than 1,000 per kW.

    The Impact of Temperature on Solar Panel Efficiency: How Heat Affects Your Solar Energy System

    Solar panels convert sunlight to electricity through a phenomenon known as the photovoltaic (PV) effect. The more sunlight they receive, the more power they can generate. Counterintuitively, if the panels become too hot, they will actually produce less electricity.

    Overheating reduces solar panel efficiency, impacting the percentage of sunlight the panel can transform into power. Read on to learn more about how temperature affects solar panel efficiency and ways to mitigate the effects.

    What Is Conversion Efficiency for Solar Panels

    Conversion efficiency refers to the proportion of sunlight a photovoltaic panel can convert into usable electricity. It’s an essential performance specification for a photovoltaic (PV) system, as it measures the maximum amount of electricity a panel can generate under peak conditions.

    Solar panel efficiency measures the maximum percentage of the sun’s rays that a PV panel can turn into electricity. Higher values indicate better conversion rates.

    Over the years, solar panel efficiency has improved significantly due to advancements in materials, manufacturing techniques, and design innovations. Today, the efficiency of consumer photovoltaic panels typically ranges from 15% to 23%.

    Laboratory tests have achieved even higher efficiencies — exceeding 40% in some cases. However, these high-efficiency panels are not yet available for the average consumer.

    The increase in photovoltaic panel efficiency over time has helped to make solar energy more cost-effective and accessible, contributing to its growing adoption as a clean, renewable energy source.

    Factors That Affect Solar Panel Efficiency

    A variety of factors can impact solar performance and efficiency, including:

    • Temperature: High temperatures will directly reduce the efficiency of a photovoltaic panel.
    • Sunlight: The amount of direct sunlight a PV panel receives is typically the most significant determiner of how much electricity it can produce. Even the most efficient solar panel can’t generate electricity at night, and production is diminished on overcast days.
    • Orientation and Tilt: Orienting panels towards the sun (facing south if you are in the Northern Hemisphere) to maximize sunlight exposure is best. Depending on your latitude, you can optimize their efficiency by angling them directly toward the sun’s path — around 30-45 degrees.
    • Dust, Snow, and Debris: Dirt, leaves, snow, and other debris can block sunlight from the panels. Be sure to clean your solar panels regularly to keep them efficient.
    • Panel Age: As photovoltaic panels age, their efficiency will slowly decrease year after year. Having said that, high-quality solar panels can last 25 years or more — longer than an asphalt roof.
    • Shading: If shadows from nearby trees or structures block your panels, they won’t reach maximum efficiency. This issue also goes for partial shading — if one cell in a monocrystalline or polycrystalline PV panel is in the shade, the cumulative electricity generation capacity of the panel will be adversely affected.

    The Relationship between Temperature, Humidity, and Solar Panel Efficiency

    Temperature, humidity, and solar panel efficiency are interconnected factors that impact the overall performance of a photovoltaic system. In general, research has found that higher temperatures reduce electrical efficiency. Humidity also plays a part, with lower humidity levels leading to increased output and efficiency.

    Solar Panels Generally Perform Better at Lower Temperatures

    As the temperature of a PV panel increases above 25°C (77°F), its efficiency tends to decrease due to the temperature coefficient. The coefficient measures how much the output power decreases for every degree Celsius above a reference temperature (usually 25°C).

    Higher temperatures cause the semiconductor materials in photovoltaic cells to become more conductive. It increases the flow of charge carriers and consequently reduces the voltage generated.

    Some PV panels feature heat dissipation mechanisms to reverse the adverse effects of high temperatures. Passive cooling or enhanced ventilation are proven methods to get photovoltaic panels closer to optimal operating temperatures.

    Humidity Can Have Both Positive and Negative Effects on Solar Panel Efficiency

    On the one hand, high humidity levels can result in increased Cloud cover and atmospheric water vapor. The clouds of humid air can scatter the sunlight or absorb it, reducing the amount of solar irradiance reaching the PV panels. Excessive humidity can also lead to the accumulation of dirt and dust on the panel surface, causing a decrease in efficiency due to reduced light absorption.

    On the other hand, humidity can also keep photovoltaic panels cooler by promoting heat transfer through evaporation and condensation, potentially mitigating some of the adverse effects of high temperatures on efficiency.

    Comparing Solar Panel Efficiency In Hot and Cold Environments

    Solar panel efficiency can vary significantly between hot and cold environments due to the influence of temperature on the performance of photovoltaic (PV) cells. Understanding these differences is essential when evaluating the suitability of PV panels for different climates and optimizing energy production.

    In hot environments, PV panels tend to be less efficient due to the negative impact of high temperatures on the performance of PV cells. As the temperature rises, the output voltage of a solar panel decreases, leading to reduced power generation. For every degree Celsius above 25°C (77°F), a solar panel’s efficiency typically declines by 0.3% to 0.5%.

    This decrease in efficiency can be significant in regions where temperatures rise dramatically during the day, such as deserts or tropical areas. In these environments, it’s best to select PV panels with a low-temperature coefficient. Also, installing cooling systems and ensuring adequate ventilation can help mitigate the effects of heat on solar panel efficiency.

    In contrast, cold environments can offer improved solar panel efficiency due to the favorable temperature conditions for PV cell performance. Lower temperatures lead to increased output voltage, boosting overall power generation.

    You should also consider other factors that might affect PV panel performance in cold climates — such as snow accumulation — which can obstruct sunlight and reduce energy production. Installing your PV panels at an optimal angle to facilitate snow shedding and ensure maximum sunlight exposure is best. Even these small changes can maintain efficiency in cold environments.

    Don’t forget to account for the reduced sunlight hours during fall and winter, which can impact overall energy generation.

    Despite the contrasting effects of temperature on solar panel efficiency in hot and cold environments, sunlight availability remains the most critical factor in determining the effectiveness of photovoltaic energy systems. For instance, a hot climate with abundant sunlight will provide more power than a cold climate without sunlight.

    Mitigating the Effects of Temperature on Solar Panel Efficiency

    Mitigating the effects of temperature on solar panel efficiency is crucial for optimal energy production, particularly in regions with high ambient temperatures. Several strategies can minimize the impact of temperature on PV panels, ensuring they continue to perform well.

    Proper installation and spacing are essential to promote air circulation around photovoltaic panels. Ensuring a gap between the panel’s rear surface and the mounting structure allows for natural convection. The airflow dissipates heat and keeps the temperature in check. Installing PV panels at an optimal angle and orientation can maximize their exposure to sunlight while reducing the likelihood of overheating.

    Selecting PV panels with a low-temperature coefficient is another way to mitigate temperature effects. Panels with lower coefficients experience a smaller reduction in efficiency as temperature increases, making them better suited for hot environments.

    Innovations in solar panel materials and designs have led to the development of advanced technologies that can better withstand high temperatures. For example, bifacial solar panels can capture sunlight from both sides. The design enables a lower temperature sensitivity and higher overall efficiency.

    Cooling Systems And Their Effectiveness

    You can also install cooling systems to manage the temperature of solar panels:

    • Passive cooling techniques — such as heat sinks and reflective coatings — effectively dissipate excess heat without requiring additional energy input.
    • Active cooling methods — like water-based cooling or forced air circulation — can further enhance heat dissipation but may involve higher costs and energy consumption.


    The optimal temperature for solar panels is around 25°C (77°F). Solar panels perform best under moderate temperatures, as higher or lower temperatures can reduce efficiency. For every degree above 25°C, a solar panel’s output can decrease by around 0.3% to 0.5%, affecting overall energy production.

    solar, panel, efficiency, does, really

    Solar panels don’t work well in heat waves due to the temperature-induced decrease in efficiency. As the temperature of the solar panels rises, their power output decreases. During a heat wave, the higher temperatures hinder the panels’ ability to convert sunlight into electricity effectively.

    Solar panels can reach temperatures around 66°C (150°F) or even higher under direct sunlight. The temperature increase is due to the conversion of absorbed sunlight into heat. Elevated temperatures can negatively impact solar panel efficiency, reducing energy production. Proper installation and ventilation can help mitigate this issue.

    Most EcoFlow solar panels have an efficiency rating of 23%. The higher rating is due to their cutting-edge design and monocrystalline structure — 23% is one of the highest ratings available for consumer solar panels. Polycrystalline panels tend to be cheaper but have a much lower rating — around 15%.

    The maximum power point (MPP) is the point on a solar panel’s IV curve where the product of current and voltage is maximized, yielding the highest possible power output. Maximum power point tracking (MPPT) is a technique employed by solar charge controllers to ensure the solar panel operates at its MPP. EcoFlow’s solutions feature MPPT controllers, which are considered superior to PWM (Pulse Width Modulation).

    EcoFlow is a portable power and renewable energy solutions company. Since its founding in 2017, EcoFlow has provided peace-of-mind power to customers in over 85 markets through its DELTA and RIVER product lines of portable power stations and eco-friendly accessories.

    Top 5 Most Efficient Solar Panels (2023 Reviews)

    This guide has helped many homeowners learn about solar panel efficiency and can help you make the right choice when deciding on the most efficient option. Let’s get started!

    Each product and or company featured here has been independently selected by the writer. You can learn more about our review methodology here. If you make a purchase using the links included, we may earn commission.

    Written by Karsten Neumeister

    Karsten is an editor and energy specialist focused on environmental, social and cultural development. His work has been shared by sources including NPR, the World Economic Forum, Marketwatch and the SEIA, and he is certified in ESG with the CFA Institute. Before joining EcoWatch, Karsten worked in the solar energy sector, studying energy policy, climate tech and environmental education. A lover of music and the outdoors, Karsten might be found rock climbing, canoeing or writing songs when away from the workplace. Learn About This Person

    Reviewed by Melissa Smith

    Melissa is an avid writer, scuba diver, backpacker and all-around outdoor enthusiast. She graduated from the University of Florida with degrees in journalism and sustainability studies. Before joining EcoWatch, Melissa worked as the managing editor of Scuba Diving magazine and the communications manager of The Ocean Agency, a nonprofit that’s featured in the Emmy award-winning documentary Chasing Coral. Learn About This Person

    Why You Can Trust EcoWatch

    We work with a panel of solar experts to create unbiased reviews that empower you to make the right choice for your home. No other site has covered renewables as long as us, which means we have more data and insider information than other sites.

    Jump to Section:

    Find the best price from solar installers in your area.

    What Are the Most Efficient Solar Panels?

    A solar panel’s efficiency rating tells you how much of the solar energy that hits your panels will be converted into usable electricity for your home. It’s not the only measure of a high-quality solar (PV) panel, but it’s one of the most important ones. Higher efficiency ratings mean your panels will generate more power in all conditions—full sun, partial sun and cloudy weather—which directly correlates to greater energy savings for you.

    We’ve looked at every top-rated major solar panel brand and the panel models offered and have determined that the below panel brands have the highest efficiency ratings in the solar industry.

    • Maxeon (formerly SunPower): Most Efficient Panels
    • LONGi Solar: Best Value
    • Jinko Solar: Best Budget Brand
    • Canadian Solar: Best Product Selection
    • REC: Best Availability

    Not all of the panels manufactured by these companies have the same efficiency rating, and some models fluctuate by a few percentage points. Below are the specific models from each manufacturer we found to be the most efficient. Note that there’s a drop-down menu available for each of these brands in case you’re looking for more information.


    The Maxeon 6 AC line of panels from Maxeon—which used to be SunPower—is best known for having the highest efficiency rating of any solar panel ever manufactured at 22.8%. Maxeon has been around for more than 35 years and has long had a reputation for outstanding quality and industry-defining technology. We recommend these panels to all homeowners who can afford them. They’re expensive, but they lead to the greatest savings over time and come with one of the best warranties available.

    What We Like

    The Maxeon 6 line of panels not only have the highest efficiency rating available, but they also now come with a massive 40-year equipment and production warranties, topping any other company we looked into. The standard in the clean energy industry is 25 years of coverage for production and manufacturer defects, and Maxeon offers 40 years of protection for both. That means ultimate peace of mind that your panels will continue performing as expected for decades.

    Maxeon and its sister company, SunPower, are also known for their commitment to quality customer service, so we expect that any warranty claim you do make will be honored.

    Lastly, for those who care about the appearance of these panels, these are all black without grid lines, so they’re about as sleek as you can get.

    solar, panel, efficiency, does, really

    What We Don’t Like

    The only bad thing we have to say about these Maxeon panels is that they’re more expensive than most other options. We do feel that the quality of the panels is well worth the investment, but they could be prohibitively costly for some solar customers.

    Solar Panel Options

    Maxeon currently manufactures two different lines of solar panels, both with inverters supplied by Enphase: the Maxeon 6 panels (AC) and the Maxeon 3 panels (DC).

    • Maxeon 6 panels: As mentioned above, these panels have the highest efficiency rating in the industry at 22.8%. They generate the most power in all conditions of any other panel, and they’re backed by an incredible 40-year warranty. The 6 is a slightly more efficient solar panel than the 3.
    • Maxeon 3 panels: Maxeon 3 panels have efficiency ratings up to 22.7%, but depending on the size of the panel you choose, that could be as low as 21.2%. The larger panel sizes come with the same 40-year warranty, but the smaller ones have the industry standard 25-year warranty.

    Warranty Information

    All Maxeon panels come with at least 25 years of coverage for manufacturer defects and performance, but all of the Maxeon 6 panels and some of the Maxeon 3 options include the company’s 40-year warranty. This covers manufacturer defects and related issues, and it guarantees that your panels will retain 88.3% of their original efficiency in year 40. This coverage is far superior to the industry standard 25-year warranty.

    Installation Options

    Maxeon is going through some changes and is working on making its sister company SunPower its exclusive installer. However, SunPower currently outsources installation to certified third-party solar companies. There are local installation companies that are able to install Maxeon panels in all 50 states.

    LONGi Solar

    Founded in 2000, LONGi is the largest solar panel manufacturer in the world, with a market capitalization nearly triple that of any competitor. Not only is LONGi one of the most successful manufacturers, but it also manages to provide outstanding value at below-average costs. The Hi-Mo 6 Scientist panels from LONGi deliver top-of-the-line efficiency ratings, and although the warranty isn’t quite as good as other panels, the upfront savings you’ll see more than make up for it, in our opinion.

    What We Like

    The Hi-Mo 6 panels reach efficiencies of 22.6%, nearly matching the industry leader. That means LONGi solar panels will help bring down your energy bills more than most other brands on a monthly and annual basis. Best of all, LONGi panels cost around 2.40 per watt, which is well below what other brands at this efficiency rating and quality cost.

    LONGi panels have a low power tolerance, which is a measurement of expected power production differential in real-world situations. The industry average is.5%/5%, and the Hi-Mo 6 Scientist model boasts a.3%/3% differential. That means you’ll see a lower production rate fluctuation, ultimately helping to maximize your energy savings over time.

    What We Don’t Like

    LONGi panels don’t have the best warranty coverage, which is really the only major downside to the brand. The Hi-Mo 6 Scientist panels come with only a 15-year warranty for manufacturer defects, whereas the industry standard is 25 years. The power production guarantee does meet the standard 25-year coverage, although the expected remaining efficiency rating after that time (88.9%) is a bit lower than some other brands that guarantee 92%.

    Solar Panel Options

    LONGi’s most recent innovation, the Hi-Mo 6 line of panels, is phasing out the Hi-Mo 4 and Hi-Mo 5 product lines. There are four different options within the new Hi-Mo 6 lineup.

    Efficiency Rating Panel Type Estimated Cost Per Watt Power Warranty Best For
    Hi-Mo 6 Scientist Up to 22.6% Monocrystalline 2.40 580W to 590W 15 to 25 years Maximum efficiency
    Hi-Mo 6 Explorer Up to 22.1% Monocrystalline 2.40 560W to 570W 15 to 25 years Extreme climates
    Hi-Mo 6 Guardian N/A Monocrystalline 2.40 N/A 15 to 25 years Self-optimization
    Hi-Mo 6 Artist N/A Monocrystalline 2.40 N/A 15 to 25 years Unique appearance

    Warranty Information

    Of the manufacturers with the highest panel efficiencies, LONGi is the least impressive. It covers manufacturer defects for 15 years compared to the 25-year standard. The power production warranty—which helps ensure you continue to save money on your electric bills—is for the industry standard of 25 years. However, it guarantees 88.9% efficiency at the end of the warranty term, whereas other companies guarantee 90% or more.

    Installation Options

    Unlike Maxeon, LONGi doesn’t have any specific partnerships, so its products are widely available and can be installed by any solar contractor that chooses to offer them.

    Jinko Solar

    Jinko Solar is another giant in the industry that provides panels across the globe. It’s best known as a budget brand, although its panels are still considered to be tier-one. We recommend Jinko panels to solar customers who want to keep upfront installation costs down but still get a high-quality brand with an above-average efficiency rating. Much like LONGi, Jinko’s panel warranties aren’t the best.

    What We Like

    Jinko Solar’s size makes its products widely available throughout the U.S. Without any specific partnerships, its panels are available from hundreds of installers in every state. The average cost per watt for Jinko panels is around 2.25, making it the most affordable high-efficiency solar panel brand on our list.

    Despite the low cost, Jinko panels are ranked quite high by PV Evolution Labs (PVEL), suggesting that the panels outperform many other brands in a variety of conditions. With a peak efficiency rating of 22.6%, Jinko’s panels are likely to boost your energy savings over less efficient options, all while saving you money on your installation.

    What We Don’t Like

    The biggest downside to Jinko Solar’s panels is the warranty coverage. Its performance warranty lasts the standard 25 years, but the degradation in the first year (2.5%) is higher than the industry average of around 2%. Plus, the remaining efficiency at the end of the term is just 80.7%, compared to the typical ~90% in other high-quality brands. The manufacturer’s warranty of 12 years also pales in comparison to the standard 25 years.

    Solar Panel Options

    Jinko currently manufactures three panel models in its Eagle lineup for U.S. customers: the Eagle G5, the Eagle G4 and the Eagle Continental. There are two additional product lines for other countries—Cheetah and Tiger—which are expected to come to the U.S. after testing.

    Efficiency Rating Panel Type Estimated Cost Per Watt Power Warranty Best For
    Eagle G5 Up to 21.13% Monocrystalline 2.40 525W to 545W 12 to 25 years Efficiency for U.S. Customers
    Eagle G4 Up to 20.96% Monocrystalline 2.40 380W to 400W 12 to 25 years Value
    Eagle Continental Up to 19.88% Monocrystalline 2.25 380W to 400W 12 to 25 years Budget Panels in U.S.
    Tiger Neo Up to 22.6% Monocrystalline 2.40 475W to 635W 12 to 25 years High Efficiency Rating
    Cheetah Up to 20.16% Monocrystalline 2.25 355W to 410W 12 to 25 years Budget Panels Outside of U.S.

    Warranty Information

    Jinko Solar has decent warranty coverage, but it’s not ideal compared to what industry leaders like Maxeon are able to offer. Jinko provides just a 12-year warranty for the equipment and manufacturer defects, which is less than half of the industry average. The power performance warranty lasts for 25 years, which is average, although the solar degradation in that time — close to 20% — is double what you’d see from higher-quality panels.

    Installation Options

    As one of the world’s largest manufacturers, Jinko doesn’t have any specific partnerships with installers. Any solar panel installation company that chooses to install Jinko panels can do so without any specific certification. That means you should have a wide selection of installers available to you if you specifically want Jinko panels.

    Canadian Solar

    Canadian Solar is a large international manufacturer that has been in business since 2001, so it has more than 20 years of experience. Its products provide an outstanding blend of quality and affordability, although the average price per watt is a little above average. We’d recommend Canadian Solar panels to homeowners looking to balance power output with affordability.

    What We Like

    Canadian Solar not only manufactures one of the highest-efficiency panel models available, but it also provides budget options—specifically, polycrystalline solar panels with a lower efficiency. This helps keep solar as accessible as possible, which we love to see from any manufacturer.

    The warranty coverage available for newer models is all in line with the industry standard in terms of length, so you should get decades of useful life and energy savings out of the company’s products.

    Finally, Canadian Solar offers more than just panels. It serves other manufacturers with raw materials that help speed up the production and increase quality of off-brand products, as well as keep industry costs down. Overall, the company has a positive impact on the solar space.

    What We Don’t Like

    The warranty coverage for everything other than the new HiHero product lineup isn’t up to the industry standards. The HiHero panels come with an above-average 30-year performance warranty plus the typical 25 years of coverage for things like manufacturer defects. The efficiency remaining after the warranty term is below average, though, at 84.8%. Most other models only come with a 15-year equipment warranty, but they do have the standard 25-year coverage for equipment issues.

    Solar Panel Options

    Canadian Solar has a pretty impressive lineup of panels that fall within two product lines: the HiKu line and the HiHero line.

    Efficiency Rating Panel Type Estimated Cost Per Watt Power Warranty Best For
    HiKu Up to 19.4% Polycrystalline or Monocrystalline 2.70 360W to 465W 12 to 25 years Affordability
    BiHiKu Up to 20.1% Polycrystalline or Monocrystalline 2.70 435W to 460W 12 to 25 years Affordability
    HiHero Up to 22.5% Heterojunction (HJT) 3.20 420W to 445W 25 to 30 years High Efficiency
    Hiku 6 Up to 21.3% Monocrystalline 2.90 445W to 555W 12 to 25 years Balancing Efficiency and Price
    BiHiKu 6 Up to 21.4% Monocrystalline 2.90 520W to 550W 12 to 25 years Balancing Efficiency and Price
    HiKu 7 Up to 21.6% Monocrystalline 3.00 640W to 670W 12 to 25 years Small Roofs
    BiHiKu 7 Up to 21.4% Monocrystalline 2.90 640W to 665W 12 to 25 years Small Roofs
    TOPHiKu 6 Up to 21.4% TOPCon Cell 2.90 420W to 570W 12 to 25 years Balancing Efficiency and Price
    TOPBiHiKu 6 Up to 21.4% TOPCon Cell 2.90 555W to 575W 12 to 25 years Balancing Efficiency and Price
    TOPBiHiKu 7 Up to 21.4% TOPCon Cell 2.90 615W to 695W 12 to 30 years Small Roofs

    Warranty Information

    If you purchase the highest-efficiency panels from Canadian Solar—the HiHero model—you get a standard 25-year product warranty plus a 30-year power production guarantee. The degradation is more significant in these panels than average at this price point, but the warranty length is still better than most companies offer.

    Other models come with a 12-year product warranty, which is less than half of what most other manufacturers provide. Most come with a 25-year production warranty—again with a faster rate of efficiency degradation than average—except for the TOPBiHiKu 7 model, which gets a 30-year efficiency warranty.

    Installation Options

    Canadian Solar doesn’t have any specific partnerships with U.S. installers, so its products are available in most areas from a massive selection of contractors. Plus, Canadian Solar is one of the few manufacturers with a vertical product line, which means its high-efficiency solar cells and other products make their way into off-brand panels. You could, therefore, end up with Canadian Solar technology even if you don’t specifically buy panels from the company.

    REC Solar

    REC is a solar manufacturer based in Norway with a massive presence throughout the U.S. By the company’s own statistics, it is the largest provider of photovoltaic (PV) modules to the United States, which is, in large part, why we think REC has some of the best solar panel availability in the country. Not only are its products widely available, but the company maintains above-average efficiency ratings across all of its products. We recommend REC panels to homeowners who want easily accessible options that will help maximize energy savings over time.

    What We Like

    REC’s performance specs and availability make it a go-to option for countless installers in the U.S., which means its products are available virtually anywhere you live. The company uses heterojunction (HJT) technology to keep panel efficiency high, which means REC panels save you more on energy bills than the average PV equipment.

    REC’s warranty coverage is also quite good, with a 25-year power production warranty guaranteeing 92% of the original efficiency at the end of the warranty term for most panel models. That’s in line with other top performers in the industry.

    REC panels also have a great temperature coefficient, losing just 0.26% efficiency per degree (C) above 25 degrees (77 degrees in Fahrenheit). That means REC panels are a great option for maintaining those high efficiency ratings and energy savings even in more extreme climates.

    What We Don’t Like

    The only real downside to REC panels is that they’re a bit on the expensive side. The high-end models cost around 3.20 per watt, before any solar tax credit is considered. The cheaper options with less impressive specs average as low as 2.50 per watt, though, so the company maintains options that will be suitable for most solar customers.

    Solar Panel Options

    REC has five primary product lines available that do a good job of providing something for everyone. This is yet another reason why we think REC is one of the most widely accessible brands in the industry.

    Efficiency Rating Panel Type Estimated Cost Per Watt Power Warranty Best For
    Alpha Pure-R Up to 22.3% Heterojunction (HJT) 3.20 410W to 430W 25 years High Efficiency
    Alpha Pure Up to 21.6% Heterojunction (HJT) 3.20 385W to 410W 25 years Warranty Coverage
    N-Peak 3 Up to 20.3% Monocrystalline 2.80 390W to 400W 20 to 25 years Balancing Efficiency and Cost
    N-Peak 2 Up to 20.3% Monocrystalline 2.80 360W to 375W 20 to 25 years Balancing Efficiency and Cost
    TwinPeak 4 Up to 20.5% Monocrystalline 2.50 360W to 375W 20 to 25 years Affordability

    Warranty Information

    For the top-of-the-line products, including the Alpha Pure and Alpha Pure-R series, REC provides a 25-year warranty for the equipment, production and labor in case a panel needs to be serviced. All other products include a 20-year equipment warranty, which is just below the industry average, and a 25-year production warranty, which is right in line with the average term.

    However, the company guarantees 92% efficiency will remain after the efficiency warranty term, which is better than most companies and in line with the best options in the solar space.

    Installation Options

    The best part about REC, in our opinion, is that it’s one of the top producers of panels in the U.S. Without being beholden to a single installer, just about any solar contractor can install REC panels, meaning the products should be available regardless of where you live.

    REC does offer a superior warranty if you have your panels installed by a REC-certified installer, so keep that in mind if you know you do want REC panels.

    What Should You Look for When Choosing High-Efficiency Solar Panels?

    Aside from your installer making sure your solar system is sized properly for your home and energy consumption, choosing high-efficiency panels is the best way to maximize your solar savings and ensure you don’t end up paying for a solar array and a high monthly electric bill.

    However, it’s not as simple as picking the panel with the highest efficiency rating. There are a few other things to consider that could change which option is actually best for your particular home. The infographic below includes a quick look at some of the most crucial things to think about that contribute to how well solar panels work in real-world conditions as opposed to standard testing conditions in a lab.

    Compare the Top-Rated High-Efficiency Solar Panels

    Overall, our top recommendations if you’re looking for high-efficiency panels are the Maxeon 6 panels from Maxeon and the Alpha Pure-R panels from REC. You might notice that our second pick actually has the fifth-highest efficiency, and that’s because we considered other crucial factors like degradation rate warranty coverage.

    The table below includes some additional information about these two panel models to help you decide which of these is the right option for your solar project. We’ll also include info for our top panel recommendation from the other providers on our list for comparison.

    Efficiency Rating Power Output Temperature Coefficient (per degree C over 25) Power Tolerance First-year Degradation Subsequent-year Degradation Efficiency After 25 Years Total Warranty Term (for Efficiency)
    Maxeon 6 Up to 22.8% 410W to 440W -0.29% 0/5% 2% 0.25% 92% 40 years
    LONGi Hi-Mo 6 Scientist Up to 22.6% 580W to 590W -0.29% 0/5% 1.5% 0.5% 86.5% 25 years
    Jinko Solar Tiger NEO Up to 22.6% 475W to 635W -0.29% 0/3% 1% 0.4% 89.4% 30 years
    Canadian Solar HiHero Up to 22.5% 420W to 445W -0.26% 0/10% 1% 0.55% 85.8% 30 years
    REC Alpha Pure-R Up to 22.3% 410W to 430W -0.26% 0/5% 2% 0.25% 92% 25 years

    Compare the Top-Rated High-Efficiency Solar Panel Manufacturers

    As far as the best manufacturers overall for high-efficiency panels, we’d have to choose Maxeon again as our number one recommendation, although our second spot goes to LONGi. All of Maxeon’s panel models come with superior warranty coverage, reliability and durability, and LONGi is a great low-cost option that still brings plenty of value for the money.

    The table below includes a side-by-side look at the product lines as a whole from these providers and the others that topped our list. We’ll include scoring for each based on our methodology, which will be explained in greater depth later in this article.

    Efficiency Score (Out of 25) Durability Score (Out of 20) Warranty Score (Out of 20) Price Point Score (Out of 20) Temperature Coefficient (Out of 10) Sustainability Score (Out of 2.5) Appearance Score (Out of 2.5) Our Overall Rating (Out of 100)
    Maxeon 25.0 19.0 20.0 6.0 10.0 1.9 2.25 84.1
    LONGi 25.0 11.5 11.0 20.0 10.0 1.25 1.25 80.0
    Jinko Solar 22.5 7.5 11.0 20.0 10.0 0.625 0 71.6
    Canadian Solar 20.5 7.5 16.0 10.0 7.0 1.9 1.5 64.4
    REC 25.0 13.0 16.0 10.0 7.0 1.9 1.8 74.6

    Which are the factors that affect solar panels’ efficiency?

    Solar power systems are considered a key tool in the energy supply for the present and future generations. Several factors have promoted the development of photovoltaics such as environmental concerns, incentives and tax deductions, a more performing and less expensive technology and the need to replace carbon fossil energy systems with renewables to ensure compliance with the objectives set by the Paris COP y limit global warming to 1.5 ° C.

    A solar cell or photovoltaic cell is a device that converts the sunlight into usable energy. The amount of sunlight that can be converted into electricity is referred to as solar cell efficiency. There are some factors that should be taken into consideration to guarantee the optimal efficiency of the solar panels.


    The temperature influences the efficiency of the photovoltaic cell due to the intrinsic characteristic of the semiconductor material. The efficiency of the solar panels increases when the temperature drops and decreases in high temperatures, as the voltage between the cells drops.

    Energy Conversion Efficiency

    The solar module has a different spectral response depending on the kind of the module. Therefore, the change of the spectral irradiance influences the solar power generation. The energy conversion efficiency is increased by reducing the reflection of the incident light.

    Solar Shadings

    Solar PV panels are very sensitive to solar shadings. Total or partial shading conditions have a significant impact rate on the capability of delivering energy and may result in lower output and power losses. Cells in a solar panel are usually connected in series to get a higher voltage and therefore an appropriate production of electricity.

    But when shading occurs, this structure presents some limitations. In fact, when a single solar cell is shaded, the current of all the units in the string is determined by the unit that produces the least current. When a cell is shaded, the whole series is virtually shaded too. To prevent the loss of energy, the installation usually includes bypass diodes.

    Bypass diodes are wired in parallel to the solar cells. When a solar cell is shaded, the bypass diode provides a current path that allows the string of connected solar cells to generate energy at a reduced voltage. Read more.

    The Orientation, Inclination, Latitude of the place and Climatic conditions

    The installation of the photovoltaic modules must take into account some factors to take full advantage of solar radiation: the orientation, the inclination, the latitude of the place, the climatic conditions. The correct consideration of these variants will help ensure that they produce maximum energy by being exposed to the greatest intensity of solar radiation for the longest period of time. Learn more.

    Operation and Monitoring

    OM services help with the management of the implementation of certain processes to avoid or mitigate potential hazards and to guarantee the optimal return on investment. Operations mainly consist of the remote monitoring and control of the PV power plant conditions and performance. Monitoring software provides access to all data collected, which can be used for different purposes: defect detection, performance analysis, improvement, predictive maintenance, and security. A good monitoring system will provide information on the production, alarms, and analytical data, in a timely, efficient, and precise manner to detect any anomaly of the PV plant. Continue reading.


    Solar panels are very durable, main warranties last for 15-25 years. However, cleaning solar panels is important to maximize the amount of light available to turn into electrical power. Making frequent physical inspections can help solar panels absorbing light effectively.

    archelios™ Suite

    archelios™ Suite is a comprehensive software solution that offers a unique approach. Thanks to its advanced computational technology, archelios™ Suite adds value to the life-cycle of any PV project: feasibility and profitability study, simulation, calculation of producible energy, complete electrical sizing, operation, and monitoring.

    The software is an efficient tool for any type of PV project.


    Trace Software – Empowering electrical solutions. Check out: Webinars eSHOP Sales Linkedin

    Share this entry

    Leave a Reply Cancel reply

    This site uses Akismet to reduce spam. Learn how your comment data is processed.

    Trace Software

    This site uses cookies. By continuing to browse the site, you are agreeing to our use of cookies.

    Cookie and Privacy Settings

    We may request cookies to be set on your device. We use cookies to let us know when you visit our websites, how you interact with us, to enrich your user experience, and to customize your relationship with our website.

    Click on the different category headings to find out more. You can also change some of your preferences. Note that blocking some types of cookies may impact your experience on our websites and the services we are able to offer.

    These cookies are strictly necessary to provide you with services available through our website and to use some of its features.

    Because these cookies are strictly necessary to deliver the website, refusing them will have impact how our site functions. You always can block or delete cookies by changing your browser settings and force blocking all cookies on this website. But this will always prompt you to accept/refuse cookies when revisiting our site.

    We fully respect if you want to refuse cookies but to avoid asking you again and again kindly allow us to store a cookie for that. You are free to opt out any time or opt in for other cookies to get a better experience. If you refuse cookies we will remove all set cookies in our domain.

    We provide you with a list of stored cookies on your computer in our domain so you can check what we stored. Due to security reasons we are not able to show or modify cookies from other domains. You can check these in your browser security settings.

    solar, panel, efficiency, does, really

    Check to enable permanent hiding of message bar and refuse all cookies if you do not opt in. We need 2 cookies to store this setting. Otherwise you will be prompted again when opening a new browser window or new a tab.

    These cookies collect information that is used either in aggregate form to help us understand how our website is being used or how effective our marketing campaigns are, or to help us customize our website and application for you in order to enhance your experience.

    If you do not want that we track your visit to our site you can disable tracking in your browser here:

    We also use different external services like Google Webfonts, Google Maps, and external Video providers. Since these providers may collect personal data like your IP address we allow you to block them here. Please be aware that this might heavily reduce the functionality and appearance of our site. Changes will take effect once you reload the page.

    Google reCaptcha Settings:

    Vimeo and YouTube video embeds:

    The following cookies are also needed. You can choose if you want to allow them:

    Leave a Reply

    Your email address will not be published. Required fields are marked *