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Types of Solar Panel Warranties

What Is Solar Panel Warranty?

The warranty of a solar panel is an agreement from a solar manufacturer, dealer or installer that assures the buyer that he is protected against panel failure and the losses and strain that come with it. The agreement which becomes effective upon purchase assures the buyer that the panel can be expected to be reliable and function optimally for a specified duration and under certain conditions. Warranty offered on solar panels vary between products and solar companies. Warranty is measured in years. Depending on the choice of solar panel brand, warranty offerings from solar panel manufacturers range from 10 to 25 years.

A warranty is in some ways a measure of the quality of the solar panel. It is an expression of the faith of the manufacturer in their product. A comprehensive warranty lasting years, even decades, not only gives customers confidence, but it shows the confidence the manufacturers have in their product. A company producing unreliable and shoddy equipment would not be able to offer a 25-year warranty on its products. Read our article on how to tell the best solar panel brands here.

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Types of Solar Panel Warranties

There are two types of warranties for solar panels:

1. Performance guarantee and

2. Product guarantee.

Product Warranty

A solar panel’s product warranty insures the integrity of the panel itself and protects the buyer against problems such as manufacturing defects, environmental issues, premature wear and tear and others.

Product warranties are to protect the buyer from defects in material or workmanship issues during the manufacturing process. The manufacturer may choose to repair or replace the product at their discretion.

Product warranties typically last from between 10-15 years for most panels and up to 25 years for premium brands.

Performance Warranty

The linear performance warranty guarantees a minimum production performance of a panel over the warranty period. This assures you that the panel will continue to have the capability to produce a specified percentage of power during the warranty period. If the panels drops below this at any time during the warranty period, a performance warranty demands that the manufacturer will fix or replace the panel.

The common industry standard is 90% and 80-83% power output production capacity retained after 10 and 25 years respectively. Premium manufacturers such as Sunpower/Maxeon and LG guarantee 88-92% power output on most modules after 25 years of use.

LG Guarantees Its Modules for Up to 25 Years

What Warranties Do Not Cover

It must be noted that warranties do not necessarily cover all kinds of failures. They do not cover defects or malfunctions caused by misuse, mismanagement, domestic accidents, abuse or improper maintenance. They also do not cover malfunctions from failure to follow operating instructions or operating appliances with which the system is not intended to be used. All these void the warranty agreement. Some manufacturers' warranty offerings include shipping and handling while others cover only the replacement panel.

Also, a warranty will only remain in force as long as the system is designed and installed correctly. Warranty agreements do not cover failures due to oversizing of systems and use of faulty components.

A warranty may also be voided if an unlicensed technician makes repairs on the system before the warranty claim is made.

Product and Performance Warranty According to Brand

Premium brands like LG, Q Cells, LONGI Solar, Hyundai, Huawei, Panasonic, REC Solar, Sunpower, offer up to 25-year warranty on their solar panels. LG offers up to 90.4% on performance warranty, Q Cells, 85%, LONGI Solar 84%, REC Solar 86%, Jinko Solar 83.1%, etc.

Other brands supported in Nigeria, A & E Dunamis, Sunshine, Canadian Solar, Amerisolar, Mitsubishi, Kyocera, Jinko Solar, Trina Solar, SolarEdge, Suntech, Sharp, Era Solar, offer between 10-15 years warranty on their panels. These other high-value brands offer mostly 80-81% performance warranty with a few exceptions.

Bankability and Warranty

Every quarter, Bloomberg publishes a BloombergNEF PV Module Tier 1 List. ( also publish a similar list as does other companies and organizations.) BloombergNEF says it started publishing the list in response to frequent request by clients for a list of 'major' or 'bankable' solar panel suppliers or tier 1 suppliers as they are commonly known in the industry for use in manufacturing forecasts, and in making analysis and comparisons.

While, the term itself Tier 1 has no unique definition and while many solar sites come up with their own based on their own set of criteria, however, according to the BNEF,

"Tier 1 module manufacturers are those which have provided own-brand, own-manufacture products to six different projects, which have been financed non-recourse by six different (nondevelopment) banks, in the past two years."

Bloomberg uses a financial criteria, bankability, to populate the list. The BNEF defines 'bankability' purely in terms of the manufacturer's access to debt financing by banks. Bankability says absolutely nothing about the quality of the panel, it however points to how strong a manufacturer is in terms of its access to a large market and financing. In other words, a Tier 1 module manufacturers must have supplied their own brand of products manufactured in their own facilities to at least six different projects larger than 1.5 MW, which were financed by six different banks in the last two years.

This system leaves us with the suspicion that it values solar module brands that specialise in large, utility projects. This gives us a list that is dominated by large conglomerates, such as Jinko, Trina, JA, LONGi, First Solar, mostly Chinese manufacturers, that are financially strong and directed towards the mass market with manufacturers of stronger brands directed towards limited rooftop and residential projects, like SunPower/Maxeon, LG subdued.

However, while we advice buyers to look beyond bankability to quality, this list is still regarded in warranty considerations because it is a way of deciding if a solar manufacturer can be expected to still be in the business during the expected lifespan of their product. If a company is financially vulnerable to sudden downturns in the solar market and if they struggle to get access to loans and capital when they need it, it becomes hard to say with any certainty if they will be around in 10 or 20 years time to be able to fulfil their warranty offerings.


To be realistic, in some cases, a warranty offering may nothing more than an effective marketing tool that serves the manufacturer rather than the buyer. This means that there are other considerations that must be taken into account when deciding which module brand to invest in. A long warranty may sound enticing but such a warranty would mean nothing if there are no convenient ways to claim it or if the company that offered it has been put out of business by financial downturns. Investing in a brand that has a local office, an after-service centre or an authorised dealer in your locale where potential warranty claims can be made directly without much hassle is a much more valuable consideration. Otherwise, a warranty offering should not be taken too literarily but seen a manufacturer's belief in the quality of its product and a determinant in the ranking of competing brands.

Also, the best roofing materials used in developed countries with high quality standards do not have a lifespan that reaches up to 25 years, much less the ones produced locally and under less stringent quality control and certification standards. As solar panels are installed to be integrated as a part of the roofing system, in 25 years the roof would have been degraded. Also as solar technology is always changing, making a warranty claim in 10 or 25 years on a panel that is no longer in production sounds silly.

For what it truly is, a warranty offering can be taken as a measure of the quality of the solar panel and an expression of the faith of the manufacturer in their product. A comprehensive warranty lasting years, even decades, not only gives customers confidence, but it shows the confidence the manufacturers have in their product.

Installation Warranty

Installation warranty is the warranty offered customers by the direct installers. In most cases, installation warranty is often a year or two years. The warranty offering by installers often covers the entire solar power system including charge controllers, batteries and inverters. It insures the owner of the system against incurring extra expenses for any failures arising from any mistakes or oversights on the part of the installers. In this case, a system must be tested in the presence of the owner and installers (in industry terms, this is called 'commissioning') and certified by both that it is working as expected.

SolarKobo's systems are designed and installed by engineers with bachelor's degrees in electrical engineering and years of experience. As is the experience of many Nigerian users of solar power systems, most installers do not follow through on their warranty offers. In addition to guarantying the best possible installation for our clients in Lagos and throughout Nigeria, and even though there is yet to be an warranty claims on our panels since our first installation, we are always willing to listen to and respond to warranty claims from our clients.

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