Solar panel warranties: What to know

We all have tasks that, deep down, we know are good for us but still dread, such as going to the dentist or getting our vehicle’s oil changed. Most would add “reviewing solar panel warranties” to that list. 

Solar panel warranties are one of the most important factors to consider when comparing your panel options, and are critical to protecting your five-figure investment. However, sifting through pages of dense documentation can be intimidating and confusing, and warranties vary by both manufacturer and panel, making direct apples-to-apples comparisons near impossible.

Fortunately, EnergySage has developed a scoring system to help consumers compare. This system takes into consideration factors such as product and power warranty terms, labor and shipping coverage, how easy it is to transfer ownership, and whether or not they cover additional equipment. 

Let’s review some of the most popular solar panel companies on EnergySage and see which offers the best warranties.

A solar panel system is a multi-decade investment that a warranty can help protect. The less solar power your system produces, the more your home may need to draw from the utility company, which eats into your savings. A good solar panel warranty ensures your solar panels maintain a certain level of performance throughout the years, protecting your expected return on investment. 

Solar panels generally come with two warranties: The product warranty covers the equipment and typically guarantees at least 10-12 years without fail, and the power or performance warranty often guarantees at least 90% production at 10 years and 80% at 25 years.

We compared some of the top solar panel companies' warranties against each other and the industry standard. Here’s what we found:

Higher ranks indicate stronger warranties, but please note that not all products from the same brand share the same warranty terms. We compared the highest-performing warranty from each company.

Solar panel warranties look different from company to company and product to product, so we developed a scoring system that makes an apples-to-apples comparison possible. Each warranty factor is weighted differently based on its importance. The warranty factors include:

We assessed and scored every company across each weighted factor and then added the individual factor scores to determine the company’s overall score. The higher the score, the better the warranty.

Also known as a materials warranty, a solar panel product warranty covers the integrity of the equipment itself. If any of your solar panels have a defect or mechanical issue, if they break or fracture, or experience unreasonable wear and tear, that's when your product warranty comes into play. Nowadays, most manufacturers offer at least 10 years of coverage under a product warranty, while some premium options have 25 or even 30+ years of protection against product defects.

*Silfab's 25-year product warranty applies to systems installed by a properly registered and qualified Silfab installer; Silfab still offers a 12-year product warranty for other installers.

**REC's 25-year product warranty applies to systems installed by a REC Certified Solar Professional; REC still offers a 20-year product warranty for other installers.

The effectiveness of electronics degrades over time, and solar panels are no exception. Because of this, solar panel companies offer a power (or performance) warranty that guarantees a certain minimal level of performance over a set period of time. This gives peace of mind to property owners concerned about the long-term return on investment.

Every power/performance warranty has two core components: The “term” and the “degradation rate.” 

Term

This sets the number of years the manufacturer is guaranteeing a certain minimum level of performance. Frankly, there's not a ton of variability across the industry; nine times out of 10, your panels will come with a 25-year power performance warranty. However, as technology advances, manufacturers are starting to offer longer warranty periods. Silfab, for example, is now offering 30 years of coverage, while Maxeon’s power warranty spans a whopping four decades.

Degradation

Solar panels degrade at slightly different rates depending on the technology used to capture sunlight, the structure of the silicon cell, and the way the panel aggregates the electricity within the panel (e.g., the layout of the actual circuitry of the solar panel). Most solar panel manufacturers will guarantee at least 80% of the original output by the end of the warranty term, or about 0.7% degradation each year.

A few things to look out for when comparing degradation rates:

• You'll notice that most warranties expect the highest degradation (2-3%) within the first year. That’s because panels degrade at the highest rate when first exposed to solar radiation. After an initial adjustment period, the panel's degradation levels off to a more stable rate.

• After year one, manufacturers typically ensure that power output won't fall by more than 0.5 - 0.7% annually for the length of the warranty term (or, if you're Maxeon, as low as 0.25% each year). When comparing one panel to another, remember to look at the guaranteed output by the end of year 25 and the protected degradation rate from one year to the next. 

• A warrantied degradation rate, like the 0.5-0.7% rate we mentioned above, differs from what you'll experience in real-life conditions. All solar panels undergo stringent testing to evaluate performance, and when manufacturers establish their power warranties, they stick to conservative numbers they feel confident in. 

Best power warranties

While the warranty may cover replacement panels or parts, that doesn't necessarily mean the manufacturer will cover the labor and shipping costs required to reinstall that equipment.

Your warranty likely won’t cover labor costs

Most manufacturers do not reimburse for the labor associated with replacements or repairs of their products (and if they do, the costs are only covered up to a certain amount). However, this usually isn’t an issue since many local installation companies will cover maintenance and repair costs within their own warranty agreement. 

A small number of solar panel manufacturers offer an extra safeguard through additional workmanship warranty coverage. It's typically only an option if you work with specific installers within a manufacturer's certified network.

Likewise, shipping is usually on you

This is an aspect often overlooked in panel warranties. Many manufacturers will cover the material costs associated with the replacement part but not necessarily the fees to ship the equipment to your house. Or, they may be able to ship the product to a local or regional distributor, but require you or your installer to get that product to your home. As with labor fees, the best warranties may cover shipping but typically have an upper spending limit for what they will pay.

Best labor and shipping warranties

*Qcells also offers an additional $250 labor coverage for battery storage systems.

Warranties exist to protect your purchase, but manufacturers also try to protect themselves from unreasonable claims. This is often known as the "fine print" – stated limitations and void clauses the manufacturer uses to protect itself. 

Here are a few limits to keep an eye out for:

When comparing one solar panel warranty to another, consider the following:

• How old is the company providing the warranty? There's a difference between a 100-year-old company offering a 25-year warranty and a 5-year-old company offering a 30-year warranty. Both exist in the solar industry. Is it a bankable company, and does it have insurance policies or an escrow to ensure its warranties will be upheld even if it goes out of business? Bloomberg New Energy Finance (BNEF) and PV Evolution Labs (PVEL) both publish lists of top-performing solar panel companies based on bankability.

• Who is on the hook to actually fulfill the warranty? Does the manufacturer have a parent company or subsidiary that backs the warranty or processes claims?

• How easy is it to make a warranty claim? Does the manufacturer allow you (the product owner) to submit the claim directly, or do you need to contact your installer? Does your installer need to come to your property and perform a diagnostic assessment before submitting any claims?

• What happens if you move? Does the warranty automatically transfer to the new system owner, or is it more complicated?

Best warranties for transferability

Some companies offer extended product or power warranties to give you added peace of mind. To be eligible for the extended warranty, you may need to choose an installer in the company's network, select a specific financing partner, or pay a fee. 

Of our top 10 companies, REC Group, Silfab Solar, and SEG Solar offer extended product warranties. If a qualified installer works on your system, those extended terms are automatically applied at no cost. Those terms are already reflected in the product scores.

Filing a claim can look different from company to company. We called all 10 solar panel companies to understand if it's easy to contact someone if necessary.