Solar PV Knowledge Bank

SunPower Solar Panels

Quick links

SunPower high efficiency solar panels.png


SunPower makes the best high performance solar panels on the market, offering up to 35% increase in lifetime generation from the same roof space and the best warranty on the market.

If you've done even the slightest bit of research on solar panels, the chances are you've come across the name SunPower. Founded and based in Silicon Valley, SunPower has come to dominate the residential solar industry with their premium high efficiency panel offering. But what makes the SunPower brand so special, if indeed it is?

SunPower: relentless innovation, backed by Total

The principal factor behind SunPower's success is its leading solar cell technology. SunPower solar cell efficiency is the best on the market.

SunPower produces a range of high efficiency solar panels with efficiencies of up to 22.6% thanks to their patented back-contact cell design which maximises usable collection area (see below). On top of market-leading efficiency, SunPower also offers the best warranty on the market, both in terms of defects and performance. Finally, SunPower is backed by Total, the world's 6th largest public energy company.

SunPower panel range

SunPower effectively offers two ranges of panels: Maxeon and Performance.


Output per panel



Maxeon 3


1,690mm x 1,046mm


Maxeon 2


1,690mm x 1,046mm


Performance Residential


1,690mm x 998mm


Performance Commercial


2,066mm x 998mm


For comparison: standard polycrystalline


1,650mm x 992mm



Sunpower Maxeon 3 White Sunpower Maxeon 3 black
Maxeon 3 - White Maxeon 3 - Black

Maxeon is the absolute premium product, with the highest efficiency of any panel on the market. Two generations of Maxeon are available, Maxeon 2 and Maxeon 3.

The panels are all sized at 1,690mm x 1,046mm.

The second generation panel, Maxeon 2, outputs range from 340W to 360W, equivalent to a peak output of 192W to 204W per square metre.

The third generation panel, Maxeon 3, has managed an impressive 11% increase in efficiency. The panel outputs range from 355W to 400W, equivalent to a peak output of 201W to 226W per square metre. The all-black versions are slightly less efficient (because the darker colour increases module temperature), and so cover the lower output range.

SunPower has also released an AC solar panel version, the Maxeon 5, which includes integrated micro-inverters.


SunPower Black Performance SunPower Performance Commercial panel
Performance Residential Performance Commercial 

Performance is a slightly lower efficiency (and less expensive product), similar to other monocrystalline panels in cost and performance. Again there are two ranges, one for Residential and one for Commercial. The Residential and Commercial panels have similar efficiencies (similar output per square metre) but the Commercial panels are physically bigger, and hence output more per panel.

  • Residential Performance Panels are sized at 1,690mm x 998mm. Outputs range from 315W to 335W, equivalent to peak output of 187W to 199W per square metre.
  • Commercial Performance Panels are sized at 2,066mm x 998mm. Outputs range from 405W to 420W, equivalent to peak output of 196W to 204W per square metre.

SunPower: cell technology

SunPower has spent over US$450million on R&D in the last 10 years; it is thus unsurprising that the company holds more than 750 patents. The underlying technology that gives rise to SunPower's superior panel performance is their patented Maxeon solar cell.

Maxeon Solar Cell
These solar cells differ from conventional cells in that they utilise back-contact technology, which means no current collecting wires ('fingers' and 'busbars') on the top surface of the cells. Maxeon cells instead employ solid copper backing sheets to provide both the positive and negative electrical connections at the rear of the cell. As a result, the top surface area is maximised for better absorption of sunlight. 

The copper foundation also offers durability advantages over the porous metal paste used for front and back contacts in conventional cells. Maxeon cells are less susceptible to cracking and corrosion - the two main causes of cell degradation. 

Sunpower cell technology

Superior performance: up to 35% higher lifetime output from the same space

The higher solar cell efficiency of SunPower equates to more output per square metre. So for example, the top performing Maxeon 3 400W panel has a peak output of 400W out of an area of 1.76m2 - that's 226W per square metre. Standard panels typically generate 168W per square metre. So SunPower enables you to install a 35% bigger system in a given roof space.

In addition, the output from SunPower solar panels degrades at a much lower rate (around 0.25% per annum for Maxeon and 0.5% for Performance, instead of the standard 0.70% degradation). Furthermore the panels exhibit superior performance in hot rooftop conditions, and in partial shade.

For example, the temperature coefficient (reduction in power output at cell operating temperatures above the ‘standard’ operating temperature – usually 45°C) is -0.27% for SunPower's Maxeon panels, compared to -0.39% for a standard polycrystalline panel, and -0.34% for the SunPower Performance range. So with a 10°C increase in operating temperature, output will drop 2.7% with Maxeon and 3.9% with standard panels. These seemingly small differences add up over many years.

Overall SunPower claims that a Maxeon 3 panel will produce as much as 35% more energy over the life from a given space than a similar rated standard panel. Just under half of this is due to reduced degradation and better 'real-world' performance, the rest is down to higher efficiency.

This ‘output premium’ is lower for other panels (see datasheets).

SunPower manufacturing

SunPower cells are manufactured in the Philippines. The modules are assembled in Mexico. The company is dedicated to making the most sustainable solar panels - the Maxeon 3 was the first to be Cradle-to-Cradle Certified.

SunPower includes the following as standard in the build of its modules, improving reliability and thus facilitating the superior warranty:

  • the SunPower panel frames use adhesives from the aerospace industry to connect to the solar laminates, and are thus designed to withstand cyclonic wind loads;
  • the cells use high grade n-type monocrystalline with minimal impurities;
  • exceptional resistance to moisture and electrical stresses provides superior reliability;
  • tin corrosion barrier: the copper foundation is plated with tin to make it nearly impervious to corrosion;
  • the SunPower panels use triple redundant cell interconnections use built-in strain relief, thus allowing for expansion and contraction from daily temperature swings;
  • anti-reflective glass with high levels of quality control ensures a uniform glass layer maximising production on cloudy days.

Superior warranty

The industry standard for solar panels is a 10-year product warranty covering manufacturing defects, along with a performance guarantee that the panels will generate at least 80% of their initial output to 25 years. There is inevitably conflict over the boundary between these two warranties: the 25 year output potentially depends on the panels not having any manufacturing defects - thus there is a lack of clarity in the value of the standard power warranty alone beyond the 10 year coverage of the product warranty. Further there is generally no full service warranty, covering the removal, installation and transportation costs of a failed panel. 

SunPower offers a superior warranty for a number of reasons, summarised in this table:


SunPower Maxeon

SunPower Performance

‘Standard’ solar panel

Panel (defects)

25 Years

25 Years

10 Years





Year 0




Annual decline




Year 25








Shipping – old panel




Shipping – new panel




Installation – new panel*




 *SunPower will pay for reasonable, necessary and actual removal and reinstallation costs of the repaired or replaced PV module up to 250 Euros for up to 5 PV modules, and 50 Euros per PV module thereafter for a single claim.

SunPower extends the defects cover over 25 years and guarantees that its panels will output 92% of their original output at the 25-year mark, rather than the 80% of the standard panel. This implies a 7% lifetime output advantage over a standard panel per watt, however, as above SunPower actually claims that their panels can produce over 20% more energy per rated Watt over 25 years.

Furthermore, in the seemingly improbable event that one of its panels does develop a fault at any point over the 25 years... SunPower will cover the complete cost of removal, replacement or repair, and reinstallation, as well as transportation costs for the return of defective panels and shipment costs for repaired or replaced panels (subject to the restrictions above).

This supreme confidence in the quality of their products distinguishes SunPower above all other manufacturers operating in the PV industry.

SunPower warranty advantage

Premium products, premium price...

SunPower panels really do represent the best quality technology on the market, but unsurprisingly this comes at a price. That said, the Performance range is similarly priced to other high efficiency monocrystalline panels, but still benefits from SunPower's 25 year warranty.

By way of example, the 360W Maxeon 2 panel will add approximately 45% to the cost of a typical small scale installation using a standard polycrystalline panel. SunPower claims that over the lifetime it will add around 35% to the output relative to that of a similarly rated system, so for this to make sense you also have to want the better aesthetics and the better warranty.

The panels definitely come into their own when space is limited, as they represent the best way to squeeze the last bit of power out of a given space.  

The 315W Performance panels will add approximately 15% to the cost of a typical small scale installation using a standard polycrystalline panel. They are much more comparable to a standard monocrystalline panel, but are generally more attractive when you consider the improved lifetime performance, reduced degradation and superior warranty.

So should you go for it?

If you can afford the additional upfront cost, we absolutely recommend you go for SunPower panels. If roof space is a limiting factor, as it often is, you will win on two counts versus a standard panel:

  • SunPower will enable you to get more out of your roof space, increasing the rated system output by up to 35%;
  • the SunPower system will exhibit superior lifetime performance, generating as much as 20% more power due to better real world performance than a similarly rated standard system.

You will also benefit from the superior warranty cover, and you'll be making a top aesthetic choice.

Request a quote

Product brochures

Discover the range of SunPower solar panels: