SunPower has been regarded as the world’s leading solar cell and panel manufacturer since the introduction of high-performance IBC solar cells in 2007. Sunpower, now known as Maxeon Solar Technologies, continues to manufacture the world’s most efficient solar panels based on patented IBC cell technology and also offers the industry’s best performance warranty, with a minimum of 92% guaranteed rated output after 25 years. SunPower’s more affordable performance or P series panels offer very high quality and great performance, as well as a 25-year product warranty.
SunPower Corporation has a long history in solar manufacturing and has long been regarded as the technology leader in the solar industry. This is a big claim, but it’s difficult to argue with them because they currently produce the most efficient residential solar panel on the market, the Maxeon 3, with the lowest degradation and best performance warranty on the market. High performance, like most things, comes at a high cost, and SunPower panels are among the most expensive in the world.
SunPower began in a lab in the early 1980s and became SunPower officially in 1988. Following investor funding, the R&D team created record-breaking PV cells using advanced cell technology, which was later used by NASA’s space program and Honda to win the world solar challenge car race in Australia. These accomplishments established SunPower as one of the world’s leading solar cell manufacturers and laid the groundwork for today’s high-efficiency Maxeon IBC cells.
SunPower has expanded and built advanced manufacturing facilities in the United States, Mexico, Europe, Malaysia, China, and the Philippines. Over the last decade, LG Energy’s Neon R range of panels, which use a similar IBC cell technology, was the only other manufacturer to compete at the same level of efficiency and performance. LG, on the other hand, has decided to stop manufacturing in the middle of 2022.
SunPower’s journey has not been without bumps. Due to high overhead costs and pressure from extremely competitive Chinese and Korean panel manufacturers, the company also ran into serious financial issues and racked up a significant amount of debt in recent years. SunPower’s financial difficulties forced it to restructure its business and manufacturing operations, and the company’s financial situation is now improving. This PV-Tech article contains a detailed company analysis.
Technology for Solar Panels and Cells
IBC Maxeon Cells
SunPower began mass production of high-performance IBC (Interdigitated Back Contact) cells in 2007 and has led the industry ever since, employing the most efficient solar cell technology available today. In contrast to conventional monocrystalline and polycrystalline solar cells, which use front-mounted busbars and fingers to collect current, IBC cells have a fine grid of conductors integrated into the cell’s rear side. SunPower’s IBC cell design, known as ‘Maxeon,’ employs a grid of N-type silicon on the back side, which increases efficiency by eliminating the need for front-exposed busbars, which partially shade the cell. The SunPower IBC cells are built on a foundation of high purity N-type silicon, which increases efficiency and performance while also offering a very low rate of degradation; this is the foundation of SunPower’s industry-leading performance warranty of 88.25% retained capacity after 40 years on Maxeon series panels.
SunPower’s current generation (3 & 4) IBC cells are 5″ (125mm x 125mm) in size and configured in a 96-cell layout with 8 rows of 12 cells. Almost all other manufacturers have adopted the 6″ (156mm x 156mm) cell size, which constitutes a common 60 cell panel. Although cell size has no effect on performance, more cells equate to a higher voltage, which can be problematic for domestic installations that have a voltage limit of 600V. (depending on the country). With a higher voltage, fewer panels can be linked together in a string before the maximum voltage is reached.
104 cell format is larger.
The Maxeon 2 and Maxeon 3 panels from SunPower are built around a new 104-cell format with 8 rows of 13 gen-3 cells to create the world’s most powerful residential solar panel at 400Wp. The Maxeon 3 panels in the full series range from 370 to 400W and replaced the older X Series, while the Maxeon 2 panels in the full series range from 340W to 360W and replaced the older E series.
Shingled cells are a tried-and-true technology that consists of overlapping thin cell strips assembled horizontally or vertically across a panel. The SunPower P series panels, which are described in greater detail below, use a vertical format with 6 long cell strips connected in parallel. As each long cell works independently, this provides several advantages, including improved shade tolerance when partially shaded. Thin shingled cells are also more flexible and resistant to micro-cracking, which is a common problem with full-size square cells. These are created by laser cutting a standard full-size cell into 5 or 6 strips and layering them in a shingle configuration with conductive adhesive on the backside. Each cell strip’s slight overlap conceals a single busbar that connects the cell strips. This unique design covers more of the panel surface area and eliminates the need for front-side busbar connections, which partially shade the cell and reduce panel efficiency, similar to IBC cells.
The P series employs traditional P-type silicon, which is less efficient than the high-performance N-type silicon employed by Maxeon IBC cells. However, it is significantly less expensive and still achieves a very respectable efficiency of 20.4%. The SunPower 25 manufacturer’s warranty also applies to the P series.
The SunPower Panel Line
While SunPower’s renowned Maxeon series panels are among the best-performing in the world, the more affordable Performance series offers a diverse range of panels for residential, commercial, and utility-scale solar installations. The new Maxeon 2 and 3 series panels replaced the previous E and X series, which competed in the premium end of the market with the same high-efficiency IBC cells. The P-series panels use the unique overlapping shingle cell design and complete more in the commercial market. Many of the Maxeon 5 and Performance series panels are also available from Enphase Energy as AC panels with integrated micro-inverters.
- 360W Maxeon 2
- 400W Maxeon 3
- 390W to 415W Maxeon 5 Series
- 400W to 420W Maxeon 5 AC Series
- 420W to 440W Maxeon 6 AC Series
- 450W to 475W Maxeon 6 Commercial
- 335W to 545W Performance Series
The Maxeon 3 is SunPower’s new flagship model, available in sizes ranging from 370 to 400W for residential installations. The new 104 cell format, based on Gen 3 high-performance IBC cell technology, increases power output and tops the range with an impressive 22.8% maximum efficiency, making it the most efficient solar panel in the world.
- Maxeon 3 – 104 monocrystalline IBC N-type cells – 400W
The new Maxeon 2 panel, like the Maxeon 3, is based on Gen 3 high-performance IBC cell technology and uses the same 104 cell format to increase power output, even more, topping the range with a maximum efficiency of 20.4%. However, because the Maxeon 2 panels are based on slightly lower-spec IBC cells, they have a lower power rating of 340 to 360W, making them more affordable while still being among the most efficient residential solar panels available.
- Maxeon 2 – 104 monocrystalline IBC N-type cells – 360W
Maxeon 5 Series
SunPower’s next-generation A series AC panels, as well as the new Maxeon 5 series, are based on Next Generation Technology IBC (Interdigitated Back Contact) ‘Gen 5’ cells. These new larger format 6″ IBC cells are manufactured on a new line at its Malaysian manufacturing plant. The new design is used to create panels with ratings ranging from 390W to 415W, making them some of the most powerful residential panels on the market today. The Maxeon 5 panel’s alternative A series version includes an Enphase Energy microinverter.
- Maxeon 5 series – 66 cell – 390 to 415W – IBC N-type cells (Gen 5)
Maxeon 6 Series
SunPower’s most recent panels, released in 2022, are the Maxeon 6 series. They are built on the same 66 cell format as the five series, but use next-generation Maxeon 6 cells to boost efficiency to a record-breaking 22.8%, making this the most efficient residential solar panel manufactured. The new six series panels are 1032mm wide by 1872mm high, which is slightly larger than the five series. Naturally, power output has been increased by 6%, raising the peak power rating from 415W to 440W. The A series version of the Maxeon 6 panel, like the 5 series, includes an Enphase Energy microinverter. The Maxeon 6 will also be available in a larger 72 cell format with increased power ratings from 450W to 475W to cater to the commercial market.
Maxeon 6 (AC) series – 66 cell – 420 to 440W – IBC N-type cells (Gen 6) Maxeon 6 Commercial series – 72 cell – 450 to 475W – IBC N-type cells (Gen 6)
The Performance series, or P series panels, use a unique shingled cell design with 6 long strings of shingled cells in parallel, as previously described in detail. This design is less expensive and provides more shade tolerance when partially shaded. The thin singled PERC cells, which are based on common P-type silicon, are more flexible and less prone to micro-cracking, which is a common problem with full-size square cells. The P series comes in three sizes, with the smaller residential panels rated from 370W to 390W, the larger format commercial panels rated from 405W to 420W, and the extra-large utility size panels rated from 475W to 500W.
P Series Residential panels – 330W to 390W – Shinged cells
P Series Commercial panels – 405W to 420W – Shingled cells
P Series Utility size panels – 475W to 545W – Shingled cells
Service And Warranty
SunPower Maxeon Technologies surprised the industry by increasing its product and performance warranty on the Maxeon range of panels from 25 years to an incredible 40 years, making it the industry’s longest solar panel warranty by a decade. Based on a detailed failure analysis program that reported an extremely low 0.005% return rate based on warranty claim data from the 15 million panels sold over the last few decades, the company is confident it can support the extended warranty.
The new 40-year warranty guarantees a minimum power output of 88.3% in year 40, implying that power output will only degrade by approximately 0.25% per year during the warranty period. Maxeon claims this is possible because of the Maxeon IBC cells’ proven long-term reliability and performance, which are built on a unique patented metal foundation. This robust cell structure can withstand high thermal stresses and dissipate more heat, making them less susceptible to hot spot formation or micro-cracks, which is a common issue with the standard cells used by most competing panel manufacturers.
Sunpower Performance or P series panels come with a 25-year warranty that guarantees a minimum of 87.2% power output after 25 years of use.
SunPower has long been the industry leader in sustainability, and it is the only manufacturer we are aware of that employs a complete closed-loop sustainability strategy. SunPower’s philosophy is to promote environmentally friendly business practices throughout the product life cycle and beyond. SunPower won the first annual Sustainability Award from pv magazine as a result of this strategy.
SunPower SunVault Residential Battery System
SunPower solar panels first entered the highly competitive energy storage market with the Equinox storage system in late 2019, but it was rebranded as SunVault Storage in 2021. The system is made up of two main components: the large module, which houses a 13kWh battery and inverter, and the smaller Hub+, which is the system’s brain and houses the load center and grid isolation equipment to enable off-grid operation in the event of a grid outage. This setup is very similar to the popular Tesla Powerwall 2. However, unlike Tesla, the SunVault uses lithium Ferro phosphate (LFP) cells, which have become the preferred chemistry for stationary battery storage systems.
The SunVault system, like the Tesla Powerwall 2 and Sonnen ECO battery systems, is AC-coupled, which means it is connected directly to the main switchboard (load center) and can also be retrofitted to homes that already have a solar system. The SunVault system, on the other hand, has a higher continuous output power rating of 6.8kW, making it the most powerful AC-coupled home battery system on the market. Up to two SunVault systems can be linked together for additional capacity, providing 26kWh of usable storage capacity, which is more than enough for most homes. The SunVault system, like the premium SunPower solar panels, is more expensive than most, costing US$16,000 plus installation.
SunPower is widely regarded as the world’s leading manufacturer of solar panels, and few companies can compete on the same level of performance and quality. SunPower continues to lead the world in overall efficiency, with the Maxeon series holding the top spot as the most efficient solar panel with the lowest degradation and best performance warranty. The Maxeon panels are also the most expensive on the market, which is unsurprising. However, as with most things, quality comes at a cost. Given that solar is a long-term investment, the higher price also translates to better performance, increased reliability, and increased energy generation over the system’s lifetime.
SunPower’s financial difficulties in recent years have raised some concerns about the company’s ability to honor long-term warranty commitments. Despite this, SunPower is still ranked first by installers and customers alike in the United States and many other parts of the world. SunPower does not have a large presence in other markets such as Asia and Australia, and the very high price of the Maxeon series can be difficult to justify when other manufacturers offer comparable performance and quality at a slightly lower price. Having said that, no other manufacturer can match SunPower’s new 40-year product and performance warranty.
The Performance series panels have also proven to be very popular in the commercial solar sector, thanks to their low cost and one of the best warranties available. With an improving financial outlook and the release of the next generation Maxeon 5 and Maxeon 6 series panels, it appears that SunPower solar panels will remain an industry leader for some time.