SunPower Solar Panels vs. LG Solar Panels

By Rex Kehoe
February 21, 2017

If you are considering installing a solar system at your home or place of business, then you have many factors to consider. The paramount factor to many buyers is which solar panels (referred to as ‘modules’ in the industry) to choose. During your solar research, you will undoubtedly come across two solar module manufacturers: SunPower and LG. Both are widely recognized as high-end modules with SunPower leading the way. So which should you choose?


SunPower is more expensive. Partnered with roughly 200 solar installation companies across the nation, Pick My Solar sees SunPower pricing to be $0.57 per Watt higher than LG. This equates to a $3,420 on the total cost for an average sized residential solar system (6,000 Watts). This is a significant cost increase for most homeowners or business owners so it’s important to understand what differentiates the two brands and their products.

Efficiency & Nominal Power

Solar module efficiency refers to the portion of energy in the form of sunlight that can be converted via photovoltaics into electricity. SunPower modules achieve a high of 22.2% with an average of 20.6%, while LG’s current products can achieve 19.5% with an average of 18.3% on the efficiency scale.

Nominal power, rated in DC Watts, is an important characteristic of a solar module to consider. SunPower’s modules range from 327W - 360W, while LG’s residential modules ranges from 275W - 320W. LG does currently offer modules as high as 370W, but these are larger in size and are typically used for commercial solar projects. Nominal power is significant because if you are a homeowner who needs a 6,000 W system to offset your electricity consumption from the Utility, you would need 17 modules with SunPower or 19 modules with LG.

Depending on how much available space you have on your roof, this may impact your decision. Also, if you plan to increase your energy consumption in the future (e.g. plan to have kids, want to get an Electric Vehicle, etc.) you may want to choose SunPower modules so you have enough space to install more modules in the future (if roof space is a constraint).

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Degradation is another characteristic of modules and it refers to their power decline over time. Most manufacturers guarantee their modules to degrade no more than 0.7% each year for 25 years. At 0.25%, SunPower’s X Series has the lowest degradation rates of any manufacturer. LG is better than average at 0.6%. After 25 years, a SunPower solar system is guaranteed to produce 92% of the electricity that it did at the time of installation while an LG solar system is guaranteed to produce 83.6%. The difference here may seem insignificant, but over the course of 25 years, this can add up.


Homeowners and business owners who are concerned with aesthetics, often choose an “all black” module with a black frame and black backsheet. SunPower and LG both offer this style. However, SunPower’s all black module has a nominal power rating of 335 Watts, while LG ‘s is rated at 305 Watts. With a similar appearance, your decision to choose SunPower or LG should rely more on available roof space and the solar system size you need.

SunPower X-21-335.png

Warranty and Bankability

These two factors are closely related and should be discussed together. Warranties provide both security and peace of mind to consumers, but if the manufacturer goes belly up, their warranty is meaningless. SunPower leads the industry with their 25/25/25 warranty, covering performance, product defects, and labor. LG covers the performance for 25 years and any product defects and labor costs for 12 years. If you have a defective solar module after 18 years, SunPower will send someone out to replace the module at no cost to you, however, LG will not. That said, If you chose an installation company that has a 25 year bumper-to-bumper workmanship warranty, then this is a moot point.

Now let’s take a look at the bankability of these two companies. Everyone has heard of LG. You may have a microwave, television, or refrigerator in your home that is made by LG Electronics. Unless you’ve looked into going solar, you likely have not heard of SunPower. Looking at the NASDAQ, SunPower’s stock price has steadily declined over the past year from $24 in March 2016 to roughly $8 today. LG stock prices have remained steady during that time period and have even risen slightly from $10 to $12. The solar industry is still relatively immature and changes in policy and advancements in technologies can have a direct impact on manufacturers. Soon after congress extended the 30% federal investment tax credit for solar in December 2015, SunPower announced 1,200 layoffs and shares quickly dropped over 30% in trading. The diverse portfolio of LG protects itself from any changes specific to the solar industry, arguably, making them a more stable and bankable company.


Coming Soon from LG

LG has developed residential solar modules that seem to truly rival SunPower. The LG NeON® R modules appear to close the gap and even exceed many of the advantages that SunPower currently has over other products. If LG keeps the price point near the current modules they offer, homeowners and business owners may have a tough time justifying SunPower’s higher cost.





Added Cost ($/Watt Adder)




Efficiency (%)




Nominal Power (DC Watts)

327 - 360

275 - 320


Degradation (%)




Product Warranty (Years)




Aesthetics (All Black)



Not Available





Going solar can be a daunting task to many as there are many things to consider. The solar modules you choose are an important consideration, but many other factors deserve more attention. Contact Pick My Solar who will analyze everything for you. If you’re ready to go solar and deciding between SunPower and LG is the last piece of the puzzle, Pick My Solar will find you the best bids for both brands in your area so you can make an informed decision. 

View our 2018 Solar Starter Guide

Have more questions or want to speak to someone regarding the best solar panels for your home? Please call (888) 454-9979. 

Still want to do more research? Continue reading our blog here or click here to see your custom savings estimate. 

This article was updated on October 20th, 2017 to reflect SunPower's latest degradation rate and power warranty .


Rex Kehoe

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Rex Kehoe

More articles by Rex Kehoe

What's Pick My Solar? We empower our customers to adopt clean energy through transparency and choice. Our free, no-obligation platform provides competing solutions from top providers.

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