110 000. This is the number of French homes that have photovoltaic solar panels on their roof (Enedis). By 2030, this number should reach 4 million homes (forecast by the Réseau de Transport d'Electricité)!
Are you planning to install panels on your roof to reduce your energy bill and do something for the planet? The question then arises as to which brand to choose, because not all brands are equal.
In the premium department, it's hard to ignore the American brand SunPowera world reference in the field, thanks in particular to its patented Maxeon® solar cell technology. What are the panels from this major player in photovoltaics really worth? We give you all the consumer reviews and our opinion on photovoltaic panels Sunpower.
Once upon a time... SunPower
SunPower was (unofficially) born out of the oil crisis of the 1970s, to which Dr. Richard Dawson was trying to respond by developing an alternative energy solution. Fascinated by the solar cells that equipped satellites, he set himself an ultimate challenge: to make these cells more profitable and more accessible. It was a quest that, nearly 40 years later, has made SunPower a leader in residential and commercial solar power generation.
While a professor of electrical engineering at Stanford, Richard Dawson obtained grants from the Electric Power Research Institute and the U.S. Department of Energy to support his research into solar energy. With these funds, coupled with financial support from two venture capital firms, he founded SunPower in 1985.
Over the years, the company has built a strong reputation for its high-efficiency solar panels, including its patented Maxeon® solar cell technology. In 2020, following an investment of nearly $300 million by Tinajin Zhonghuan Seminconductor Co. (TZS), SunPower spun off its manufacturing division to create Maxeon Solar Technologies (alongside SunPower), a Singapore-based company dedicated to the production of solar panels, marketed under the "SunPower" brand. The company has manufacturing facilities in France, Malaysia, Mexico, China and the Philippines.
That same year, SunPower is ranked the top commercial solar solutions provider in the U.S. for the third year in a row. Also in 2020, the manufacturer launches a brand new system, called OneRoof™, a rooftop solar panel specifically designed for new homes.
Since its (official) inception in 1985, SunPower has been a company that has achieved many innovations... some would say feats:
- SunPower's high-efficiency solar panels helped a Honda car win the 1993 World Solar Challenge, a race across Australia, beating the second-place car by a full day;
- In 1997, SunPower's high-efficiency solar cells powered NASA's Pathfinder prototypes, high-altitude solar-powered drones. That same year, the Pathfinder Plus model reached an altitude of 21,800 meters, a record;
- In 2007, SunPower began mass production of its record-breaking high-efficiency solar cell with an average conversion efficiency of 22.4 %;
- In 2008, SunPower announced a prototype monocrystalline silicon solar cell with an efficiency of 23.4 %, a world record at the time;
- In 2009, PlanetSolar chose SunPower's high-efficiency solar cells to power the world's largest solar-powered catamaran.
SunPower Photovoltaic Panels
When you hear the name SunPower, the first word that usually comes to mind is this: Maxeon. This is the manufacturer's flagship model, and it comes with a 40-year warranty, the longest in the solar industry!
Maxeon's patented solar cell technology includes solar panels with very high efficiency and exceptional reliability and durability. In addition to the historic Maxeon line, SunPower also offers a "Performance" series. Here's an overview.
Maxeon, SunPower's historic line
SunPower's Maxeon solar photovoltaic panels feature a "back contact," a solid copper panel that serves as a connector, boosting the surface area of production and extending the life of these panels, which have a special place in the residential photovoltaic landscape.
Of course, longevity comes with preserving product performance, with one of the lowest annual production drop rates on the market. Maxeon continues to produce at 92 % of its rated power after 20 years of service! The rear panel protection delays wear and tear.
Another key advantage of SunPower's residential PV panels is that they are the only ones with a peak power output of more than 430 Wp, the highest in the residential solar panel market.
The Maxeon range is available in several models, each offering different levels of performance and efficiency:
- Maxeon 3Maxeon's most efficient solar panel: with a conversion efficiency of up to 22.7 %, it is the ultimate in residential solar panels. The Maxeon solar cells in this panel are designed to resist corrosion and thermal stress, ensuring exceptional durability and reliability. Maxeon 3 panels are available in wattages ranging from 390 to 430W.
- Maxeon 6 Maxeon 6: With an efficiency of up to 22 %, this solar panel is an attractive option for those looking for a good compromise between cost and performance. Maxeon 6 solar panels are designed to provide maximum energy production, even in high temperature and low light conditions. They maintain good efficiency on cloudy days. Each panel has an integrated microinverter that operates independently, limiting the impact of shadows and improving overall system performance. Maxeon 6 panels are available in power ratings from 410 to 435 W.
Whether you choose a Maxeon 3 or 6 series model, SunPower is committed to offering you:
- A 40 year warranty, covering the product and the power;
- A minimum guaranteed power in the first year of 98 % ;
- A maximum annual degradation rate of 0.25 %.
Performance" range, an excellent quality-price ratio
Unlike the Maxeon series, the Performance solar panels use high-efficiency PERC monocrystalline cells, not back-contact technology. The power range is slightly lower than the Maxeon series (375 Wp to 415 Wp) and the maximum efficiency of the Performance series is 21.1 % (Performance 6 panel).
Again, the Performance line is available in two flagship models, each offering different power levels:
- Performance 3 : available in powers from 370c to 390 Wp ;
- Performance 6 : available in powers from 375c to 415 Wp.
In broad terms, the Performance range is distinguished by the following features:
- The Performance Series uses PERC (Passivated Emitter Rear Contact) monocrystalline solar cell technology, which provides better energy efficiency than traditional solar cells. This technology also improves the performance of solar panels in low light conditions;
- SunPower's Performance solar panels show an efficiency of up to 20 %, which is slightly lower than Maxeon solar panels...but still within the market average at this price point;
- The Performance line is designed to withstand harsh weather conditions and is backed by a 25-year warranty on product performance and quality.
Aesthetics of SunPower PV panels
SunPower promises one thing: you won't have to choose between aesthetics and functionality. Indeed, the American manufacturer strives to combine the two, and the bet is rather successful.
In our opinion, SunPower's solar panels are aesthetically pleasing, thanks in part to the use of anti-reflective glass that reduces glare, making them suitable for various architectural styles. We are particularly impressed by the black lacquered panels, not only the frame, but also the support and the cells, without losing any performance.
Ideal solution for slate roofs, these panels are integrated like a Velux window. The cables are hidden under the panels for a more flattering look.
The performance of SunPower photovoltaic panels
Remember that solar panels perform best when they are kept at a temperature around 25°C. To measure the performance of a solar panel, we use the temperature coefficient, an indicator that shows how much the performance of your panel changes during the hot and sunny days of summer.
For every degree above 25°C, your solar panel's power output will decrease by its temperature coefficient. The temperature coefficient of all SunPower panels is 0.29 %/°C. This means that if the temperature of the panel increases by one degree from 25°C, its electricity production will decrease by 0.29 %. If its temperature rises to 35°C, the electricity production will decrease by 2.9 %... a great performance.
On the efficiency side, recall that SunPower launched the first 400W residential solar panel in 2019. At the time, this panel was the most efficient residential solar panel in the world, with an efficiency of 22.6 %. The Maxeon 2 and Performance 3 solar panels also have impressive efficiencies of 20.4 % and 19.9 %, respectively.
On another note, solar panels typically lose 2.5 % of power in the first year of operation (and 0.7 % each subsequent year), whereas SunPower PV panels guarantee a minimum of 98 % of power in the first year. This means that a typical solar panel will retain 80-82 % of its rated power after 25 years, whereas the Maxeon line has an industry-leading maximum annual degradation rate of only 0.25 %, remaining around 88 %.
This is made possible by the high-performance Interdigitated Back Contact (IBC) cells, which SunPower began mass-producing in 2007. SunPower's IBCs are built on a high-purity N-type silicon base that increases efficiency and performance at a very low degradation rate. This is the basis for SunPower's highest performance guarantee of 88.25 % of retained capacity after 40 years on Maxeon series panels.
To help you see things more clearly, here is a table summarizing the main performance indicators of the two flagship models in the Maxeon and Performance lines (Maxeon 3 and Performance 6):
|SunPower Maxeon 3||SunPower Performance 6|
|Number of cells||104 cells||104 cells|
|Type of cells||Maxeon Gen III Monocrystalline||Single crystal PERC|
|Output power (peak)||400 Wp||410 Wp|
|Nominal voltage||65,8 V||29,9 V|
|Panel efficiency||22,6 %||20,9 %|
|Annual power degradation||0,25 %||0,45 %|
|Dimensions||1690 x 1046 x 40 mm (1.77 m²)||1808 x 1086 x 30 mm (1.96 m²)|
|Weight||19 kg||21 kg|
|Product Warranty||40 years old||25 years old|
|Performance guarantee||40 years old||25 years old|
|Operating temperature range||- 40 °C to 85 °C||- 40 °C to 85 °C|
User reviews of SunPower solar panels
For the media, there is no doubt: SunPower is THE reference in photovoltaic panels. But what do users think? Overall, the reviews are largely positive, as evidenced by this selection of verified reviews.
" When I called SunPower to find out what the cost would be compared to the other products I had evaluated, the company was competitive, which surprised me. In fact, the price was significantly lower than the previous offer I had gotten, partly because the yields are very high and the quality offered by the other product would require more panels, which would increase the cost. " (March 31, 2022)
" We decided to go solar with SunPower on the recommendation of our university's alumni association. We had been wanting to go solar for some time, but we needed a company we could trust. SunPower met our expectations by providing excellent service. " (March 17, 2023)
" I decided to add a photovoltaic system to my home to make it more energy efficient. It's important to me to run my home primarily on green energy to reduce my carbon footprint. I chose SunPower because they provided me with the most cost-effective solution, the best product platform and the best long-term support. " (March 17, 2023)
" We had a great contact person who helped us move the process forward, but others in the company were not as responsive and did not move the project forward. I went solar both to save money and to be environmentally friendly. " (March 16, 2023)
SunPower's strengths and weaknesses
SunPower is a global leader in the industry and has a lot going for it. Let's recap:
- Highest conversion rate on the market: SunPower panels are capable of converting more sunlight into electricity, with a conversion rate of up to 22.8 % ;
- A record 40-year warranty on Maxeon products and performance, and a 25-year warranty on all others;
- The panels retain over 88 % of their power after 40 years;
- Reviews of SunPower solar panels are largely positive, and the brand is popular with experts and users alike;
- Broad product portfolio: SunPower offers panels primarily for residential installations, but also flexible panels, high-efficiency modules for commercial installations and dual-function panels. The company also offers energy storage systems.
SunPower also has weaknesses, but they are far outweighed by the advantages:
- SunPower's solar panel prices are among the highest on the market, if not the most expensive;
- SunPower focuses more on residential projects. While the company does offer panels for commercial and mobile solar installations, this is not its specialty. As a result, SunPower's panels for these applications are not as advanced and competitive as those of the competition.
What are the alternatives to SunPower?
The first that comes to mind is DualSun, a quality alternative and 100 % French to SunPower. Combining reliability and (especially) innovation with its hybrid panels, DualSun offers more than respectable performances, coupled with a beautiful robustness.
Read our opinion on Dualsun photovoltaic solar panels
Other alternatives to consider
True to the reputation of its parent company, LG Solar offers robust solar panels with an attractive yield. In terms of innovation and performance, SunPower is always one step ahead, but LG Solar's photovoltaic panels also have their strengths: elegant design, good performance, generous warranties and an attractive price-performance ratio.
In addition, some other major industrialists have also entered the photovoltaic market. These are Ikea, a big name in furniture, and Oscaro Power, a big name in spare parts. You are free to consult the Oscaro Power solar panels opinion or the opinion on Ikea panels which also makes PV panels via its specialized partner.
SunPower review: verdict
Are SunPower PV panels worth it? If you have the budget, the answer is "yes"! SunPower solar panels are well worth the price, and are among the best on the market. It's hard to find fault with them.
SunPower remains one of the world's leading solar panel manufacturers, thanks in part to the Maxeon line, which has cemented the American brand's status as a leader. But quality comes at a price, and Maxeon panels are the most expensive on the residential market.
After studying mechanical engineering, Julian entered the world of climate engineering in 2009. After having built his experience in the ventilationand then in the heating with the largest manufacturers of German origin, he became an entrepreneur in the renewable energies and in particular a specialist in heat pump and solar panels photovoltaic systems for thehabitat individual.