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Solar Panel Performance and Product Warranties – Are You Being Over Promised?

Do you believe that your solar panels will have a 25-year warranty on them? Well think again my friend, solar panels have two widely used manufacturer warranties one, the performance warranty, which is mainly to look pretty and can easily be misconstrued to persuade you of a great deal, and is also hard to enforce. The other is simply the one that is enforceable and has merit – the product warranty. Now there is a third contender subtly emerging from the retailer/installer, which is a subsequent performance warranty but still not widely offered or enforceable.


You are also entitled to an inverter warranty usually around 5 years with options to increase, racking/mounting system warranty around 10 years, and installation/workmanship warranty should be at minimum 5 years. But I won’t discuss these further here.

Let’s break down the solar panel warranties.


I’ll start with the manufacturer’s performance warranty, this, for the most part, is just an enticing figure that can easily sell you the product on the basis that it is a very long warranty. Incidentally, if it’s not understood or explained properly or maybe even twisted on purpose to lure you into accepting an offer based on the extent of the coverage. These performance figures are based on the expected degradation of the cells of the panels and how they will perform over 25 years. This warranty is a guarantee, and the parameters will be displayed on the specification sheet, it guarantees the panels or cells will only lose a specific amount of the output capacity over 25 years. I believe this warranty to be a little bit sticky because it is hard to enforce for the simple reason it would be really hard to prove any problems. Think back to my last two articles that touched on factors that affect the output of the system, because of these factors it would be really difficult to determine that your system is degrading slightly quicker than promised. Let’s consider this warranty as an expected performance guideline only and the higher the percentage that is expected at the 25 year mark i.e. slower degradation rate, is the better choice, and not the warranty that you could expect to rely on should your panels slightly underperform. However, if you were up for a fight and you believe that your panels are not performing as promised, then you could assert your right under the Australian Consumer Law ‘express warranties which this performance warranty may be seen as an additional promise, especially if it was sold to you on this basis. But to be fair, do your research and don’t allow yourself to be gullible and sold a product on this promise alone. I am merely pointing this out, as some companies will intentionally sell products based on this information.


There now is a subsequent performance warranty gathering momentum that needs to be mentioned here because although it is not common with the small small-scale installations (<100kW)…yet, it is becoming common with large-scale (>100kW) installations, and one can only assume this will inevitably filter into both residential and business small scale installs. This emerging guarantee has some solar companies making their own performance promises, say over the next ten years output of x amount will be generated, guaranteed, and if not then the company may be liable for the cost of the discrepancy. Would I guarantee this? Absolutely not! And especially without limitations. Here’s why, there is simply the potential to overpromise and underperform, some companies will do this just to make the sale, and therefore forcing other businesses to have to make the same promise just to stay competitive. But it puts businesses at risk if they did have to pay out large amounts of money for compensation, and again I touch on underperforming can be hard to prove with all the factors that contribute to how the system actually performs. An article by Chunn, J. (2019, June). Solar’s Broken Promises Ecogeneration outlines companies offering these performance warranties, independent of the manufacturer, on products that they do not produce themselves nor have any power over the quality control process of these products. So how could I be expected to guarantee this? If you are offered this warranty ask yourself, ‘is this just to get me to sign on the dotted line?’ If a company does not offer this promise it doesn’t necessarily mean someone is being dodgy, it may actually mean they are being business smart, and realistic. Historical weather data helps determine what is expected to be generated along with the standard testing conditions of the panels, if the weather is different or there is a year of cloudy days, do you really expect a company to pay for this, or be blamed for the underperformance? This may in fact be a promise that just cannot be kept, and if good quality panels are being offered, I don’t believe this subsequent warranty is necessary. So be wary if you are offered this on top of the other warranties, at a minimum ask how they expect to determine if the panels are underperforming, and the limitations of the warranty, because this could be an easy one to sidestep.


On a more positive note, the warranty you can rely on is the product warranty. This one is fairly straightforward, and it protects the consumer from faulty or defective workmanship or materials during the manufacturing process. Most manufacturers are offering around 10-12 years as a standard but some, not many, are offering higher right up to 25 years in LG’s case. But you will pay for this, they will be more expensive, but that’s up to you whether you want to fork out extra for that long a warranty.


What I really want to point out here is how the confusion can manifest from the 25 year performance warranty accidentally or on purpose being misconstrued to the most trusting of person and sold with belief that there is a 25 year product warranty in place. Please ask the question, more than once if you have to for clarification or even look on the specification sheet yourself to distinguish between warranties. Below are two performance warranties displayed differently, but this will help you know what the performance warranty may look like, the Trina Honey 275-305W and the LG NeON® 2 325 – 330W from their respective specification sheets.




Figure 1. Performance warranty Trina Honey 275-305W



Figure 2. Performance warranty LG NeON® 2 325 – 330W


Trina Honey shows the Product warranty and the Performance Warranty or Linear Power Warranty together, stated in the second line of figure 1 as 10 years and 25 years respectively. In LGs case the warranties are separate on the specification sheet, figure 2 shows the performance warranty only. Knowing the difference between performance and product warranties is important, and the performance warranty generally has a graph showing the expected linear decline.


Something else to think about, even if a product seems to have a good product warranty, who pays for the testing, and if required, the shipping of the panel to the manufacturer? Do your research. Some panels will offer in their product warranty, that testing, shipping, and replacement are all covered, some will offer that it is up to their discretion what they will cover, I mean for Pete’s sake if you want me to buy your product say what you mean, panels aren’t easily shipped off somewhere for fixing or replacement.

Which also brings me to my final word on this, I beg you, use a panel manufacturer that has offices in Australia, that way if you do have problems and need to contact them yourself, or worse case, have to ship a panel somewhere, you have that support in Australia. Cheapest shouldn’t be the determinant with solar panels, paying the extra for panels from a reputable manufacturer that is accessible, and reliable are other factors to consider when comparing quotes. After all, you’re the one outlaying a bucket load of money for a very long-term investment, and you should be getting what you are promised with the necessary support.


I will do a follow up article for inverter and installation warranties at a later date because the next article will discuss rebates and financial incentives as of the 1st of July the Vic Solar Home package will be up and running again, so this certainly needs clarification, along with some other incentives.

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Melinda Glew