Compared: Solar panel warranty information for SunPower, LG, Panasonic and Canadian Solar



Compared: Solar panel warranty information for SunPower, LG, Panasonic and Canadian Solar

If you’re interested in getting in on the sustainable, clean energy offered by solar panels, you’ve likely done some research on top solar manufacturers already: SunPower, LG, Panasonic and Canadian Solar.

Each of these providers are well-known and respected in the solar market, but each offer different products and features for your solar upgrade. In particular, buyers should pay attention to the solar warranties offered by each provider.

Your solar warranty protects your system—and your investment—from defects, performance issues, or other disruptions that affect your solar installation. Every manufacturer offers a standard warranty on their products, but there’s a lot of variance in these contracts across companies.

Make sure you review these details and read all of the fine print before committing to a manufacturer.

What kinds of solar warranties are there?

Solar warranties come in several varieties:

  • Solar panel product warranty: This is the standard “manufacturer’s warranty” that you’ll see on most commercial products. This warranty covers defects in workmanship and protects buyers against faulty equipment.
  • Solar panel power warranty: Every solar panel—regardless of manufacturer—degrades over time, limiting the amount of power it puts out. Power warranties offer assurances that solar panels will provide a set amount of energy at various points throughout its lifecycle.
  • Combined power and product solar panel warranty: Some manufacturers offer combined power and product warranties, but note that these bundles aren’t always as comprehensive as they seem. Be sure to read the fine print and verify that the warranty covers both the product and power in a way that suits your needs.
  • Solar performance guarantee: Performance guarantees are similar to power warranties, but with a few key differences. Power warranties promise that a solar panel will put out a certain wattage over its lifetime; performance guarantees relate to how many kilowatt-hours a system puts out over a given time period.
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What’s the difference between warranties and performance guarantees?

To illustrate the difference, consider the angle of your solar installation and how it affects performance. If you don’t work with a certified installer who can guarantee your panels get maximum sun exposure throughout the year, your system performance will suffer.

Naturally, meeting a performance guarantee relies on quality equipment, correct installation, and ongoing maintenance. Most manufacturers don’t offer performance guarantees unless you work with a manufacturer-approved vendor for installation and maintenance.

What do solar panel warranties cover?

The specifics of each warranty depend on what manufacturer you go with and what warranty types they offer. Most manufacturers offer standard warranties for their products, with some offering extended warranties for an additional fee.

Generally, product warranties cover the basic operation of standard solar equipment, such as panels, inverters, or batteries. There may also be additional protection against inclement weather, such as hail stones or tornado damage included in your solar warranty.

Of course, most providers offer power warranties bundled with their product warranties, so you’ll have some assurance that your panels will perform as they should—at least for a little while. The performance degradation of each panel depends on the manufacturer and the product purchased, so make sure you know the differences going in.

What’s the SunPower solar panels warranty?

SunPower is unique in the solar market with its comprehensive 25-year power, product, and service warranty. The SunPower warranty covers solar panel power output, protects against manufacturer defects, and even covers service fees like repairs, replacements, or reimbursements of defective panels.

  • Standard length: 25 years
  • Annual power decline: 0.3% Power output:
  • >92% over 25 years

[Related article: Are SunPower the best solar panels for your home?]

What’s the LG solar panels warranty?

Another well-known entity in the solar market, LG offers a 25-year product and power warranty on its solar products, similar to SunPower. LG’s size works to its advantage, here. As a solar leader, the brand features high levels of consumer trust and certainly has the capital to back up its warranty claims.

  • Standard length: 25 years
  • Annual power decline: 0.4%
  • Power output: >90.02% over 25 years

[Related article: LG solar panels - are they a good choice for your home?]

What’s the Panasonic solar panels warranty?

Panasonic’s solar warranties vary based on product, with most entries coming with a 25-year limited product warranty. They also have a limited power warranty promising that solar panels will retain at least 90.76% of their power output capability across the 25-year warranty timespan.

  • Standard length: 25 years
  • Annual power decline: 0.26%
  • Power output: >90.76% over 25 years

[Related article: Are Panasonic solar panels the best option?]

What’s the Canadian Solar solar panels warranty?

Canadian Solar offers a standard 10-year product warranty on its panels with an extended 25-year power warranty. While respectable, this Canadian Solar comes up short compared to the extensive warranties offered by other industry-leading solar manufacturers.

  • Standard length: 10-year product, 25-year performance
  • Annual power decline: 0.7%
  • Power output: >80% over 25 years

[Related article: Are Candian Solar solar panels right for your home?]

Are snail trails or hotspots covered under solar panels warranties?

Both “snail trails” and hotspots are relatively common issues to affect solar panels long-term. Though they’re caused by different things, they both represent localized decreases in efficiency that can reduce the total power output of a solar installation.

Need to contact a solar installer in your area? SolarReviews details the top solar installers in the country

Unfortunately, these issues often aren’t covered under product warranties. This is where it pays to read the fine print before signing on—all solar warranties have a “limitations and exclusions” rider that details when the manufacturer warranty will not apply. Snail trails and hotspots are often included in these exclusions.

However, if the issues significantly decrease system performance, or if the issues are caused by improper installation, these issues may be protected. Make sure you understand the details of your solar warranty and be aware of these issues.

It’s hard to know what the future will hold, particularly for long-term investments like solar installations. Warranties protect your investment and ensure that your panels work the way they should—do your research and compare your options side-by-side before buying.

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Additional resources

 - Author of Solar Reviews

Andrew Sendy

Solar Industry Expert

Andy is arguably the most qualified rooftop solar expert in America. He is in a unique position, having founded a large solar company but now being independent of any particular company. He has appeared on CNBC, has been referenced in public hearings concerning the rooftop solar industry ( such as the recent CPUC NEM 3 decision) and has been referenced by many major publications such as the Wall Street Journal, Business Week and many others.

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