Contractor Blog

SunPower's 40 Year Warranty is a Game Changer

George Riley · 09 Feb 2022

Last week we tuned into a SunPower webinar, which promised a vague ‘big reveal’. We expected a new product or partnership, but what we got was a bombshell - Maxeon Solar Technologies (the company that makes SunPower panels) is extending its warranties to an epic 40 years for new installations.

Not only does this blow competitors’ 25 years warranties out of the water, it fundamentally changes the perception of solar power. We’ve long expected that panels will outlast their first 25 years, but for the first time a manufacturer is guaranteeing four decades of performance. You’re now buying 40 years’ worth of clean electricity upfront and that changes everything about your payback period and return on investment.

You’re buying products for life.

SunPower warranty details

The new SunPower warranty covers all three elements for 40 years:

  • Product - 40 year warranty on workmanship and materials defects.
  • Performance - guaranteed minimum of 88.3% power output after 40 years.
  • Service - repairing or replacement of defective panels covered for 40 years (this isn’t often the case with competitors’ warranties, particularly with labour costs).

The 40 year warranty applies to SunPower Maxeon panels installed on or after 1st January 2022.

To qualify for the 40 year warranty, the panels must be registered with Maxeon within 6 months of the warranty start date. Otherwise, a 25 year warranty applies.

SunPower vs standard panel warranties

Even without the additional 15 years, the SunPower warranty guarantees a significant performance uplift compared to standard panels, due to reduced degradation:


SunPower Maxeon panel

Standard panel

Year 1



Annual decline



Year 25



Year 40



Over the years, this adds up to a lot of extra warranted power:

Warranted panel power comparison

And when we say a lot more warranted lifetime power, we really mean it - over 60% more in fact. SunPower Maxeon panels will typically increase the upfront system cost by about 30% so, if you can afford the premium price tag, in the long run, SunPower makes sense.

Why do SunPower Maxeon panels last longer?

SunPower Maxeon panels use Interdigitated Back Contact (IBC) technology, the patented difference that sets them apart from other modules and makes them more durable:

  • Each cell has a solid metal backing, which makes it stronger and more resistant to corrosion from the elements.
  • Daily temperature changes can cause the connectors between solar cells to expand and contract (and eventually break). Maxeon cells use extra thick connectors to counteract this strain and add triple redundancy.
  • SunPower panels have been proven to perform better in shade from clouds or soiling, which helps to protect against hot spots developing and causing electrical failure.

Jeff Waters, CEO of Maxeon Solar Technologies, said: “We have spent more than 35 years refining the patented cell and panel design of our IBC technology and that has provided the confidence that our panels will last for more than 40 years in the field.”

Promoting solar power

This news should also be positive for the solar industry more widely. A 40 year warranty will reassure people that solar panels will last for decades to come, making them an even more worthwhile investment, and an even more sustainable source of power generation.

For more information on solar PV, download our recently updated Specifier’s Guide to Solar:

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Topics: Maintenance, Solar PV