Comparing solar warranties

How to compare solar panel warranties in 2022

If you think comparing solar panel warranties is confusing, you’re certainly not alone. Even if you take the time to sift through pages of dense documentation, understanding the differences in warranties across the various manufacturers can feel like comparing apples to oranges! We sat down with some of the top solar panel companies to better understand their individual warranties, and to get a feel for the key warranty factors to be on the look out for. To help you compare different company’s warranties, we developed a scoring system that allows you to compare different options head to head. In this article, we’ll explain our scoring system and break down how each of the companies stack up against one another.

This is an unbiased review: EnergySage is not paid to review brands or products, nor do we earn money from affiliate advertising in this article. The content of this blog is based on research and information available at the time of writing. Learn more about our mission and how we make money as a company.

Key takeaways

  • Choosing a solar panel brand should depend on a number of factors, including cost, efficiency, power output, performance, and warranty
  • The most important warranty characteristics to compare include product warranty term, power guarantees, labor warranty term, transferability & bankability, and the availability of an extended warranty
  • Based on our ranking system, SunPower has the strongest overall warranty, with Panasonic and LG Solar close behind
  • The best way to make your solar panels last is to choose an excellent installer: visit the EnergySage Marketplace to access our network of pre-vetted solar installers

What’s in this article?

The EnergySage warranty scoring system

Solar panel warranties aren’t exactly straightforward – so, we developed our own scoring system to facilitate comparison between warranties from different solar panel companies. Each factor of a warranty has its own unique scale within the rating, which we determined based on its importance. The warranty factors include:

  • Product: How many years does the warranty cover the integrity of the equipment itself?
  • Power at year 25: What percentage of initial power output is guaranteed at year 25? This is also often referred to as a performance warranty.
  • Labor: Is the work needed for any diagnostics, repairs, or replacements covered by the manufacturer warranty? Is it up to a certain dollar amount?
  • Shipping: Is the transportation of any components needed to be diagnosed, fixed, or replaced covered?
  • Extended product warranty: Can you extend your product warranty by paying more?
  • Extended 30-year power warranty: Does your power warranty extend to 30 years (either automatically, or at an additional cost)?
  • Transferable: If you sell your house, how easy is it to transfer your warranty to the new owner? Do you have to fill out any paperwork or does it transfer automatically?
  • Bankability: What happens if the company goes out of business or stops manufacturing panels? Will your warranty still be covered? We use a few different metrics here, as bankability can be difficult to quantify. First, Bloomberg New Energy Finance (BNEF) is an industry standard tool; Tier 1 panels are considered the most bankable. Second, PV Evolution Labs (PVEL) conducts independent testing to assess the quality and bankability of panels and releases a list of top scorers. And third, we assess if companies have a separate warranty reserve, escrow, or insurance company that backs their warranties.
  • Inverter: Does the warranty extend to the inverters in the system?
  • Racking equipment: Does the warranty cover the racking equipment for the system?

For more information on the warranty factors, be sure to check out our solar panel warranty overview article, which goes into depth about what each factor means. 

Product<15 years-<20 years<25 years-25+ years
Power at year 25<85% at year 25-<90% at year 25-<92% at year 2592% at year 25
LaborNoSometimesYes, up to a costYes--
Extended product warrantyNoYes, not automatically----
Extended 30-year power warrantyNoYes, not automaticallyYes, automatically---
TransferabilityYes, with exceptionsYes, but you have to file paperworkYes, automatically---
BankabilityLittle information available• Additional certifications;
• Third party testing; or
• Established counter-party
• Top performing PVEL score• BNEF Tier 1;
• Has cash reserve;
• Has escrow; or
• Has insurance policy.
InverterNot covered-Covered---
Racking equipmentNot covered-Covered---

We assessed and scored every company across each factor – but please note that each factor was weighted based on importance and thus they don’t all have the same number of available points. We then summed the individual factor scores to determine the overall company score. The higher the score, the better the warranty. For example, a company’s warranty could offer: 

  • 20-years for product (3) 
  • 88% at year 25 for performance (2)
  • No coverage of labor (0)
  • No coverage of shipping (0)
  • Extended product warranty up to 25 years at a cost (1)
  • No extended 30-year power warranty (0)
  • Unlimited ownership transfers if you fill out paperwork each time (1)
  • BNEF Tier 1 bankability (3)
  • No inverter coverage (0)
  • No racking equipment coverage (0)

In this case, based on each factor score, the manufacturer’s warranty overall score would be 10 points.

Compare solar panels based on various factors in the EnergySage Buyer’s Guide

While it’s important to compare warranties when choosing a solar panel company, they’re just one part of the equation. You’ll want to consider a number of factors when making your decision including cost, efficiency, power output, and performance. Using the EnergySage Buyer’s Guide, you can compare the warranties, performance, and aesthetics of top solar panels. There’s a lot in there, so we recommend using the filter and sorting functionalities to find the right solar panel for you.

How do the top solar panel warranties compare?

Based on our ranking system, we compared 10 of the top solar panel companies against each other and the industry standard. While making your decision for which solar panel to buy should be based on a number of things, including cost, efficiency, power output, and performance, warranty is an important consideration as well. 

Click the image below for a full side-by-side comparison:

*REC’s 25-year product warranty pertains to systems installed by a REC Certified Solar Professional; REC still offers a 20-year product warranty for other installers.
**Silfab’s 25-year product warranty pertains to systems installed by a properly registered and qualified Silfab installer; Silfab still offers a 12-year product warranty for other installers

Please note that warranties vary by product for some companies. The scoring system is based on the highest performing company product for each factor. Higher ranks indicate stronger warranties. To enlarge the image, right click and open in a new tab.

Most importantly, the company’s overall ranks are as follows:

LG Solar21
Aptos Solar13
Industry standard1

Please note that higher scores indicate stronger warranties. It’s also important to be aware that LG Solar is exiting the solar industry in June 2022; however, they will continue to uphold their warranty.

Our ranking system shows SunPower with the leading warranty, with Panasonic and LG Solar close behind. 

Best for hardware warranty

The following companies all offer 25-year product warranties. In addition, their warranty extends to the full system, including inverters and racking equipment:

  • SunPower: with SunPower microinverters
  • Panasonic: under AllGuard Warranty, bundled with Enphase microinverters
SunPower25 yearsYes, 25 years for SunPower microinvertersYes9
Panasonic25 yearsYes, 25 years if panels bundled with Enphase microinverters in AllGuard WarrantyYes, with AllGuard warranty9
LG Solar25 yearsYes, 25 years for LG NeON R ACe series panels which come with integrated LG microinvertersNo7
REC25 yearsNoNo5
Q CELLS25 yearsNoNo5
Silfab25 yearsNoNo5
Solaria25 yearsNoNo5
CertainTeed10 yearsYes, 25 years for microinverters/ power optimizers, 12 years for string invertersYes4
Aptos Solar15 yearsNoNo2
AXITEC15 yearsNoNo2
Industry standard10 yearsNoNo0

Please note that higher scores indicate stronger warranties.

Best for power warranty

The following companies all have power warranties that guarantee at least 92 percent output in year 25 for at least one of their products:

  • SunPower: DC panels
  • Panasonic: EverVolt panels
  • LG Solar: NeON R panels
  • REC: Alpha panels
SunPower92% DC, 90% AC at year 255
LG Solar92% NeON R, 90.08% NeON 2 at year 255
Panasonic92% EverVolt, 90.76% HIT at year 255
REC92% Alpha, 86% REC N-Peak & TwinPeak 4, 80.7% REC TwinPeak (60-cell), 85.5% TwinPeak (72-cell) at year 255
Q CELLS86% G10+, 85% for all other panels at year 252
Silfab85.1% at year 252
Aptos Solar85.1% at year 252
Solaria86% at year 252
AXITEC85% at year 252
CertainTeed80.2% at year 250
Industry standard80% at year 250

Please note that higher scores indicate stronger warranties.

Best for labor warranty

The following companies cover labor for diagnostics, repairs, or replacements without a cost limit as long as the initial installation was conducted by an installer certified in the company’s network; they also cover shipping of components:

  • SunPower: 25 years for SunPower affiliated installers
  • Panasonic: 25 years if installed by Panasonic Authorized installer and registered through Panasonic within 60 days of Warranty Start Date
  • CertainTeed: 25 years for Master installers, 15 years for Certified installers
SunPower25 years with SunPower affiliated installersYes5
Panasonic25 years if installed by an Authorized Installer and registered within 60 days of Warranty Start DateYes5
CertainTeed15 years for Certified installers, 25 years for Master installersYes5
LG Solar25 years, up to $450 in labor costs with an LG PRO installerYes4
REC25 years for REC Certified Solar Professional installers for systems <25 kW (10 years for systems 25-500 kW)No information available3
Q CELLS25 years, up to $250 in labor costs for solar panels registered through Q.PARTNER program and less than or equal to 25 kW*No2
Aptos SolarNoYes2
Solaria25 years, up to $300 for the first visit and no more than $200 for the second visitNo2
Industry standardNoNo0

*Q CELLS also offers an additional $250 in labor for battery storage systems
Please note that higher scores indicate stronger warranties.

Best for bankability & transferability

The following companies are all highly bankable, meaning they’re either BNEF Tier 1 or have a separate cash reserve to ensure warranties are paid out. Additionally, if you move and need to transfer your warranty to the new owner of your home, you won’t have to fill out any paperwork – the warranty will automatically transfer throughout the warranty period:

  • LG Solar: BNEF tier 1
  • Aptos Solar: 1% cash customer reserve for every panel sold
  • Q CELLS: BNEF tier 1
LG SolarAutomatically transfers to new system owners• BNEF Tier 1 company
• Holds a general warranty reserve on balance sheet for which the counter party is LG Electronics USA Inc.
• Top performing PVEL score
Aptos SolarAutomatically transfers to new system owners• Extensive third party testing
• 1% cash customer reserve on every panel sold to ensure warranties are paid out
Q CELLSAutomatically transfers to new system owners• BNEF Tier 1 company
• Top performing PVEL score
• Backed by Fortune Global 500 company Hanwha
SunPowerMust fill out transfer paperwork• BNEF Tier 1 company
• Large warranty reserve separate from balance sheet
• Top performing PVEL score
RECMust fill out transfer paperwork• BNEF Tier 1 company
• Top performing PVEL score
SilfabAutomatically transfers to new system owners• Top performing PVEL score4
SolariaAutomatically transfers to new system owners• Conducts additional third party testing3
PanasonicMust fill out transfer paperwork• Panasonic Life Solutions is a well-established counter-party with a diversity in products2
AXITECAutomatically transfers to new system ownersLittle information available2
CertainTeedSolstice system can be transferred only one time in first 10 years• ISO, IEC, ISO certifications on manufacturing facilities & inspectors in facilities1
Industry standardMust fill out transfer paperworkLittle information available1

Please note that higher scores indicate stronger warranties. It’s also important to be aware that LG Solar is exiting the solar industry in June 2022; however, they will continue to uphold their warranty.

Best for extended warranty

Warranty extensions can apply to two different warranty factors: product and power. Of the 10 companies on our list, one offers an extended product warranty and three offer power warranties that extend to 30 years.


  • Aptos Solar: for a cost, increases from 15 year baseline to 25 years


  • Silfab: automatically guarantees 82.6% at year 30
  • Aptos Solar: for a cost, guarantees 82.4% at year 30
  • Solaria: via a select finance partner, guarantees 83.5% at year 30
SilfabNo*Yes, automatically guarantees 82.6% at year 302
Aptos SolarYes, to 25 years at a costYes, 82.4% at year 30 at a cost2
SolariaNoYes, 83.5% at year 30 via a select finance partner (contact Solaria or installer directly to take advantage)1
LG SolarNoNo0
Industry standardNoNo0

*Silfab and REC both technically offer extended product warranties as well but these are automatically applied if the installation is done by an installer in their certified network at no cost to you; thus, these are reflected in the product warranty score.
Please note that higher scores indicate stronger warranties.

What to know when filing a solar panel warranty claim

While we don’t include the claim process in our scoring system specifically, we do think it’s important for you to understand! So, we’ve summarized some important information about each company that will help you if you have to file a warranty claim:

Aptos SolarFirst contact installer, if customer can't reach installer, submit claim in writing by mail to Aptos SolarSanta Clara, CA408-931-60548:30am - 5pm PST Mon - FriAfter a menu, will likely send you to voicemail
AXITECContact AXITEC in writingLogan Township, NJ856-393-78008:30am - 5pm EST Mon - FriNo menu, straight to a person
CertainTeedContact installer or contact CertainTreed directly through website or over phoneMalvern, PA800-345-11458:30am - 5pm EST Mon - FriMenu, a person will likely answer after prompts
LG SolarContact installer or contact LG Solar directly in writing or via emailHuntsville, AL800-243-00008am - 6pm CST Mon - SunMenu, a person will likely answer after prompts
PanasonicContact installer or Panasonic directly and submit claim form with required photos via email-Only online--
Q CELLSEmail or write to claims department if in purchase agreementIrvine, CA949-748-59968am - 5pm PST Mon - FriAfter a menu, will likely send you to voicemail
RECNotify installer, need proof of original purchase and must include description of defect and product's serial number in claimAcross the United States877-890-8930No hours listedNo menu, straight to a person
SilfabContact installer, installer will submit a return merchandise authorization on your behalf, can also contact Silfab directly via email or phoneBellingham, WA360-569-47338:30am - 5pm PST Mon - FriAfter a menu, will likely be placed on an automatic hold
SolariaEmail or write to claims department directlyFremont, CA510-270-2507Open 8am - 5pm PST Mon - FriAfter a menu, will likely send you to voicemail
SunPowerNotify installer and contact SunPower directly by phone or via emailPhilippines800-786-769324/7Menu, a person will likely answer after prompts

Find a company with a great warranty on EnergySage!

A solar system is a long term investment – typically they last 25 to 30 years! And while solar panels generally need very little upkeep and rarely break, having a strong warranty can give you peace of mind when going solar. The best way to make your solar system last? Choose an excellent installer! On the EnergySage Marketplace, you’ll receive up to seven quotes from our network of pre-vetted professional installers, offering equipment with some of the best warranties. If you’re looking for a specific panel brand, simply make a note in your EnergySage profile. 

If you represent a solar panel OEM and don’t see your company’s warranty included in this article, please reach out to

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Categories: Buyer's Guide

About Emily Walker

With over five years of experience in environmental science and clean energy, Emily is an expert in solar, battery, and energy management technology and policy. She holds a Master of Science in Environmental Science and Policy from Johns Hopkins University and a Bachelor’s Degree in Environmental Science and Biology from Colby College. Emily is always looking for ways to live her life more sustainably and is currently in the process of electrifying her home.