Who Makes the Best Solar Panels?
December 8, 2021
Determining who makes the best solar panels can be challenging, especially with the proliferation of solar companies over recent years.
In this article, we present the most important considerations to evaluate the quality of solar panels and share recent findings from third-party review sites.
You can use several criteria to evaluate the quality of solar panels:
- Efficiency and yield
Efficiency and Yield
Efficiency refers to the amount of power produced at peak daylight as sunlight is absorbed. For example, if a solar panel is rated at 20% efficiency, then 20% of the sun’s energy that hits the panel will convert to solar energy to use for power electricity.
Yield, on the other hand, is determined by:
- High-temperature performance
- Spectral response (i.e., the ability to capture energy from reshifted sunlight in the morning and evening)
- The use of anti-reflective glass, or ARG (which enables the panels to capture more light when it’s cloudy or when the sun isn’t directly overhead)
- Shade performance
The primary determinant of solar panel efficiency is the materials used in the panels. The most efficient material is monocrystalline silicon.
Other materials also make a difference, including a panel’s conductive metal foundation, the type of glass used on the front of the panel, and the interconnects between the cells. Thin lines of metal ribbon on the front of a cell indicate that a panel is at increased risk of breakage compared to those with a copper-backed foundation.
Most standard efficiency solar panels range from an average of 15% to 20% efficiency. The largest global manufacturers of standard efficiency panels include Trina Solar, JinkoSolar, and Canadian Solar. U.S.-made solar standard efficiency panels are available from Mission Solar.
Commercially available high-efficiency solar panels range from about 18% to 22%. Solar companies who make high-efficiency panels include SunPower, LG, REC, Panasonic, and Silfab Solar. All SunPower panels have an efficiency rating between 21.7% and 22.8% (excluding the U Series).
However, there are limits to the maximum potential efficiency of solar cells. Solar radiation in different parts of the country, roof pitch, azimuth (horizon angle), the direction your panels face, and temperature all affect solar panel efficiency. Additional energy loss may also be associated with the length and type of the cabling, voltage limits, and inverter efficiency.
These related performance measures have a direct impact on how much power your system will produce per watt installed. Making sure you have the most recent energy efficiency information will afford you the highest return on your investment over the lifetime of your solar panels.
[Related: Where to Install Solar Panels]
The expected lifetime of equipment and the length of time a company will guarantee its performance are correlated. Here are three considerations to keep in mind when evaluating a solar manufacturer’s warranty:
- Equipment: Ask about the warranty coverage for performance and materials. Make sure you understand if there are different guarantees on the inverter, monitoring, and other equipment in addition to the panels.
- Process: Ask about the warranty services provided. Be sure to understand the required steps to file a claim and assess whether the company will make it easy for you to replace, repair, or get reimbursed for any defective parts.
- Longevity: A warranty is only as good as the issuing company’s reputation. If your solar company goes out of business before the end of the term, you could be left without coverage. Make sure you’re confident that the manufacturer will be around for the duration of your warranty period.
[Related: What to Expect: Your HOA and Solar Panels]
A solar panel’s durability is another indicator of its quality. Several reputable third-party organizations independently test solar panels. Their ratings will give you an idea of how well yours will hold up in harsh conditions such as storms, hurricanes, hail, and more over time.
Fraunhofer is an applied research organization with world-renowned solar power technology expertise. They assess panels from nine top PV manufacturers for resistance to humidity and thermal cycles, potential-induced degradation (PID), mechanical loading, and UV light exposure.
TÜV, a global leader in product safety validation based in Germany, conducts Sandstorm Testing to evaluate the harsh stresses of desert conditions. DNV-GL issues an annual PV Module Reliability Scorecard. The scorecard is based on their Product Qualification Program using independent laboratory testing of solar panel reliability across multiple manufacturers.
However, the National Renewable Energy Laboratory (NREL) is the primary government-run lab for renewable energy testing.
Keep in mind that rain, clouds, or an accumulation of debris, dirt and dust can impact your system’s energy generation. So if you’ve noticed more inclement weather days than normal over recent months or the past year, or if your panels need a thorough cleaning, it may be the cause of reduced energy production rather than any issue with the system itself.
Contact your solar installer or the solar panel manufacturer for assistance if your system is underperforming and none of the above factors are the cause.
Aesthetics are very important for some buyers, although they’re considered a “soft” measure of quality for the most part.
The current appearance trend for solar panels leans toward less visible, including black backing (also referred to as black-on-black panels). Coming years will likely see various styles of solar roof tiles, which Tesla has introduced and now sells on a commercial scale.
Solar panel quality also relates to a manufacturer’s commitment to responsibility in their products, operations, and impact on other stakeholders. The best solar panels have a minimal impact on the environment during the manufacturing process as well as at the end of their lifecycle.
Several organizations provide benchmarks on sustainability in the solar PV supply chain. The Cradle to Cradle Certified™ designation assesses products in terms of safety toward human and environmental health, design for future use cycles, and sustainable manufacturing.
The Silicon Valley Toxics Coalition (SVTC) produces a biannual Solar Scorecard that assesses solar manufacturers using sustainability and social justice benchmarks. Solar panel manufacturers can also participate in the Declare platform, which provides transparency into a product’s origins, ingredients, and end-of-life options such as recycling.
Top Solar Panel Manufacturers
Several websites provide unbiased assessments of the best solar panels from leading manufacturers across the U.S. and world.
EnergySage rates the top 46 manufacturers according to efficiency, temperature coefficient range (which measures the loss in power output as the temperature rises), and warranty after reviewing the technical specifications for thousands of panels.
The top manufacturers by category according to their analyses are:
- Efficiency: SunPower, Panasonic, LG, and Solartech Universal all have greater than 20% for their most efficient panels.
- Temperature coefficient: Stion, Silevo, Panasonic, and SunPower panels are all below -0.3%/degree Celsius.
- Warranty: SunPower, Panasonic, and Solaria all have 25-year warranty plans.
Here are the top 8 mosts efficient solar panels as of 2023:
|Solar Panel Model
|Maximum Rated Efficiency*
|3. Canadian Solar
|4. REC Group
* According to Solar Reviews published product data sheet as of 2023
According to EnergySage, the top company names most commonly associated with best solar panels for home installation include the following:
- REC Group
- Q Cells
- Canadian Solar
- Trina Solar
Tips for Shopping Solar
Know What You’re Getting
Ask your local solar provider which brand of solar panels they sell and distribute before installing them in your home. Request details about the manufacturer, their make and model, and warranties associated with each component of your system, from the panels to the inverter.
Don’t Take Their Word for It
Seek out independent analyses and tests comparing the performance and durability of solar panels. Search as many online reviews as possible and try to talk with someone who currently owns and generates power from the panels you’re considering to get a first-hand opinion.
Trust Your Gut
At the end of the day, the best solar panels are the ones that fit your needs. Everyone has a different threshold for cost and quality, as well as different time horizons for desired financial return.
Contact Freedom Solar for SunPower Solar Panels
Solar panel company SunPower by Freedom Solar was recognized as the 2017 “Residential National Dealer of the Year” and “Residential Regional Top Producer of the Year” for consistently putting customers first, demonstrating exceptional industry knowledge and leadership, and installing more residential solar than any other dealer in the central U.S.For more information or to begin your solar journey, contact us today. Call +1 (800) 504-2337 or complete our online inquiry form to request a quote and begin your free consultation.