What’s the Difference Between a Product and Performance PV Module Warranty?

Manufacturer warranties on solar PV modules instill confidence for homeowners as well as for the companies who install them. These warranties provide assurance regarding the durability and energy output of solar modules, offering protection against defects and performance degradation over time. Understanding the terms of these warranties is essential so that you can properly explain their coverage to your customers. 

In this quick excerpt from the Customer Contracts & Agreements course, David Dunlap, the VP of Product Strategy at BayWa r.e., explains the difference between PV module product and performance warranties.  

So if we get into PV specifically, I mentioned product and performance. So there you’re talking about the product just wasn’t manufactured properly, right? Is the frame straight? The glass is uncracked? All the connections, the solder connections, are solid? Everything works electrically? 

Then you get into performance and all modules will have a detailed… the first year, you can expect X amount of drop in output as the panel “burns in” I guess is a way to think about it, right? You first fire it up and start running it, it’s going to lose some of its efficiency in the first year. After that, it settles in and it has sort of a very low slope, long degradation over time. 

The warranties will say something like, “it’s a 25-year performance warranty with a guaranteed output of at least 84% of the original watt class on the nameplate rating after 25 years.” 

What that means in practice is that that module is going to keep on producing electricity for many, many years. We’ve heard about some of the initial early solar pioneers that installed modules in the 70s and 80s and those things are still making power. They didn’t make a lot of power in the early days and they still aren’t making a lot of power, but they do still make some power. 

So the warranty has to differentiate between – yes, it still works – versus no, it’s not working the way it was designed to work. Right? If an entire string of cells somehow fails, that would be a defect, but it would come under the performance warranty because it would be measurable as  it’s only been five years and this thing is only producing 66% of its rated power. So that’s a performance warranty claim issue. That’s a lot of detail on modules, but that’s kind of how they break down. 

On the product side, some of the larger global and US-manufactured brands have gone to a 25-year product, 25-year performance. Then in some cases we see 30-year performance, or in the case of Maxeon SunPower, maybe even up to 40 years. So pretty extreme. 

And again, what does that tell you about the manufacturer? Confidence in their product. They think they’re building the best quality product and they believe it’s going to last longer than their competitors. And hopefully they’re charging more to be in line with that value that they think they’re creating in that product.

Want to dig deeper into all the types of warranties that you’ll come across in solar installation? Enroll in the Customer Contracts & Agreements course to learn more!