Best of the Best: Comparing the Top 5 Solar Manufacturers

Kenneth Wilson

You’ve decided to invest in solar power. Great! You’ve made a great choice for the environment and for your own pocketbook. However, the next question you probably have is which kind of solar panels should you buy? After all, there are well over a dozen prominent companies on the current market that produce solar powers. How do they compare and how do you know you’ll get the best possible product for your money? Let’s take a look at the top solar manufacturers and how they stack up to one another.

Key Metrics

Before getting into the comparisons of manufacturers, it is important to discuss the different metrics that make sense for comparing them. There are three primary metrics that are excellent for comparing solar panels: efficiency, temperature coefficient, and warranty.


Solar panel efficiency notes percentage of sunlight that is able to be converted into usable energy. For example, if a solar panel has an efficiency rating of 21%, that means that 21% of the sunlight it receives is converted to power. With this metric, a higher number is better.

Temperature Coefficient

Like all electrical products, solar panels see loss of performance in extreme temperatures. Temperature coefficient measures this loss in terms of degrees Celsius. If a temperature coefficient is -0.4, this means that the panel will produce 0.4% less electricity production for every increase in temperature of one degree Celsius above 25 degrees (77 Fahrenheit). While this is a very small decrease, it can add up.


This is the easiest factor to compare. Warranties cover the solar panels and their major components, meaning that any failures due to manufacturing defects are replaced free of charge as long as the warranty is in place. Obviously, a longer warranty is more ideal.

LG is a household name which gives them credibility to start with. They have a wide range of solar panels and also provide a concierge services that helps homeowners to find the perfect solar system for them with a free analysis. This is a particularly useful tool as many homeowners struggle to determine the optimal size of a solar system for their home.

LG’s solar panels are known to be quite durable and have a high efficiency, ranging from 18.4% to 22% depending on which panel type is selected. Their temperature coefficient ranges from -0.4 to -0.29. They also have a warranty on their products of 25 years, which is tied for the longest in the industry.

Panasonic is another household name that is well-known in the electronics industry. Thus, it is not a surprise that they are one of the top brands in terms of solar panels as well. Panasonic’s options include the EverVolt, AC, and HIT series. Consumers ca find either traditional or all-black designs in all three series.

When looking at the metrics for Panasonic, the efficiency performance has a narrower range than LG but a lower maximum, ranging from 19.1% to 21.2%. Temperature coefficients are very low, at -0.26 for all panels which is tied for best performance in the industry. Finally, Panasonic also provides a 25-year warranty on its solar units.

REC Solar may not be a household name, but this California company has established itself as a leader in the industry. They provide three residential options, the Alpha, N-Peak, and Twinpeak Mono Black. The company focuses on high quality, high-output products which shows in their overall performance.

When evaluating performance of REC, efficiency ratings have a fairly extensive range with a low of 16.5% and a high of 21.7%. The temperature coefficients range from -0.26 to -0.37. Finally, the warranty on REC products is 20 years. While this is at the low end of our list, it is still a good warranty as most manufacturers have warranties of 10 years.

Another California company that specializes in solar systems, SunPower offers a wide variety of solar power generation and storage options for customers. The company has been operating since 1985 when it was the creation of n engineering professor at Stanford University. It offers four different lines of solar panels: the P-series, E-series, X-series, and A-series with the P-series being the more affordable and the A-series the best performing.

In terms of overall energy efficiency, SunPower has a fairly wide range from 16.5% to 22.8%, but also has the highest performing panels in the industry. The temperature coefficients of their products range from -0.29 to -0.38. They also have a 25-year warranty.

Final Thoughts

While there are a wide variety of solar panel manufacturers on the market, LG, Panasonic, REC, SunPower, and SolarTech comprise five of the best manufacturers. Their metrics can be compared as noted below:






18.4% - 22.0%

-0.29 - -0.40

25 years


19.1% - 21.2%


25 years


16.5% - 21.7%

-0.26 - -0.37

20 years


19.0% - 19.9%


15 years


16.5% - 22.8%

-0.29 - -0.38

25 years

The company you want to go with will likely vary based on your needs. If you are looking for high efficiency, SunPower leads the way. For those in very hot environments, Panasonic, REC, and SolarTech provide the best temperature coefficients. For those wanting peace of mind, LG, Panasonic, and SunPower have the best warranties in the business.

Kenneth Wilson
April 22, 2021

Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done. I also operate remodeling design service for homeowners.

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