SunPower solar panels review: Efficient, effective & expensive
SunPower is widely recognized as the gold standard of solar panels, but are competitors finally closing in on that gap?
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Image credit: SunPower
The longstanding leader of solar panel efficiency is also the most expensive option on the EnergySage Marketplace.
SunPower solar panels are best for those looking to install a highly efficient solar panel system that can easily integrate with other products, like a solar battery. From solar panels to hardware, SunPower sells complete solar energy systems for residential and commercial applications. At the heart of its operations is its cell technology, which is the most efficient on the market.
At $3.49 per watt, SunPower is not for budget shoppers. It’s better suited for solar enthusiasts willing to spare no expense on the best of the best. But, keep in mind that Maxeon Solar Technologies no longer exclusively sells to SunPower, meaning you can install Maxeon's panels without the SunPower bill (but still at a premium).
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Key Takeaways
Prices
$3.49 per watt on average, based on more than 10,000 real-world quotes on the EnergySage Marketplace in the second half of 2023.
Federal tax credits and state, local, or utility incentives should further reduce the price. The federal solar tax credit alone reduces the cost by 30%.
Pros
Amazing specs: SunPower solar panels lead the industry in efficiency ratings and have some of the best temperature coefficients and degradation rates, too.
Standout warranty: SunPower’s 25-year Complete Confidence warranty is one of the most comprehensive warranties available.
Lots of equipment under one brand: The SunPower Equinox Home Solar System comes with built-in microinverters and all necessary hardware, which easily integrate with its solar battery.
Cons
Price: SunPower solar panels are the most expensive on the EnergySage Marketplace.
Shifting business dynamics: SunPower lost its exclusivity with Maxeon in March of 2024. A month later, the CEO announced other key business decisions made to boost financial viability, which affected its workforce and residential direct sales operations.
SunPower’s cell technology has earned the company its reputation as the most efficient on the market. Although it no longer manufactures its own products, SunPower designs three lines of residential solar panels: SunPower Maxeon (M-Series), SunPower Performance (P-Series), and the U-Series.
Maxeon Solar Technologies, SunPower’s former manufacturing arm, produces the Maxeon and Performance panels. A few different companies, including Waaree, manufacture the more budget-friendly U-Series panels.
SunPower solar panels
Maxeon 3 | Maxeon 6 | Maxeon 7 | Performance 3 | Performance 6 | Performance 7 | U Series | |
|---|---|---|---|---|---|---|---|
| Cell type | tated back contact (IBC) | tated back contact (IBC) | tated back contact (IBC) | Shingled | Shingled | Shingled bifacial | Mono PERC |
| Power output | 355–430 W | 410–445 W | 435–445 W | 370–385 W | 395–415 W | 440–455 W | 395–415 W |
| Efficiency | 201.1%–22.7% | 21.2%–23% | 23.5%–24.1% | 18.9%–19.6% | 20.1%–21.1% | 21.7%–22.4% | 19.8%–20.8% |
| Temperature coefficient | −0.27% / °C | −0.29% / °C | −0.27% / °C | −0.34% / °C | −0.34% / °C | –0.29% / °C | -0.37%% / °C |
| Warranty | 25 years | 25 years | 25 years | 25 years | 25 years | 25 years | 25 years |
| Warranted degradation | 98% of output in year 1, at least 92% in year 25 (0.25% degradation rate) | 98% of output in year 1, at least 92% in year 25 (0.25% degradation rate) | 98% of output in year 1, at least 92% in year 25 (0.25% degradation rate) | 98% of output in year 1, at least 87.2% in year 25 (0.45% degradation rate) | 98% of output in year 1, at least 87.2% in year 25 (0.45% degradation rate) | 99% of output in year 1, at least 89.4% in year 25 (0.4% degradation rate) | 98% of output in year 1, at least 84.8% in year 25 (0.55% degradation rate) |
| Weight | 42 lbs | 48 lbs | 46 lbs | 49 lbs | 46 lbs | 55 lbs | 49 lbs |
| Size | 41.2 x 66.5 x 1.6 in | 40.6 x 73.7 x 1.6 in | 40.7 x 70.4 x 1.6 in | 45.7 x 66.5 x 1.4 in | 42.8 x 71.2 x 1.2 in | 44.6 x 70.5 x 1.2 in | 40.9 x 75.7 x 1.4 in |
For solar panels, the most important specs to watch are:
Efficiency: How well a solar panel captures sunlight and converts it into electricity for your home, expressed as a percentage (i.e., 22.2%). The higher, the better.
Temperature coefficient: How well your solar panels perform in less-than-ideal conditions, expressed as a percentage per degree (i.e., 0.34% / °C). The lower, the better.
Warranty: Guarantees that the company will replace your panel if it fails due to manufacturing defects or environmental issues. Warranties also guarantee a certain amount of production throughout the 25+ year term.
SunPower vs. other popular brands
Sun Power Maxeon 3 420W | REC Group Alpha Pure-R 420W | QCELLS BLK M-G2+ 420W |
|---|---|---|
| 46.7 lbs | 47.4 lbs | 47.2 lbs |
| 66.5 x 45.7 x 1.4 in | 68.1 x 44.0 x 1.2 in | 67.8 x 44.6 x 1.18 in |
| $3.49/W | $2.82/W | $2.89/W |
| 22.2% | 21.8% | 21.9% |
| −0.27% / °C | -0.26 % / °C | −0.30 / °C |
| 25 years | 25 years | 25 years |
| 98% of output in year 1, 0.25% annual degradation after that | 98% of output in year 1, 0.25% annual degradation after that | 98.5 % of output in year 1, 0.33% annual degradation after that |
*Price reflects the average price per watt based on more than 10,000 real-world quotes on the EnergySage Marketplace in the second half of 2023. It is not specific to the model listed.
Top-notch solar panel technology
Maxeon's technology, which SunPower uses for some of its panels, is the best of the best. The monocrystalline, half-cut cell structure reduces heat loss because the cells are smaller, making them more efficient than conventional panels. The Maxeon-produced solar panels enhance efficiency even more through interdigitated back contact (IBC) and shingled solar cell technology.
IBC cells have electrical contacts on the back rather than on the front like conventional solar cells. This eliminates any metal grid-like lines on the front of the panel, allowing for the entire front of the cell to absorb sunlight. The back of the panel is held together with a layer of durable copper to prevent corrosion and other common causes of failure.
Shingled solar cells are regular cells cut into strips and arranged like shingles on a roof. Instead of using metal ribbons to connect the cells, shingled solar cells use an electrically conductive adhesive (ECA), boosting flexibility and durability.
The U-Series panel uses Passivated Emitter and Rear Contact (PERC) solar cells. PERC cells include a back surface layer that reflects light back through the cell, reduces heat absorption, and reduces electron recombination, all of which lead to improved panel efficiency.
You can get everything under one brand
SunPower solar panels conveniently come with built-in microinverters and all necessary hardware through the SunPower Equinox Home Solar System. The advantage of purchasing your whole system from one company is its integration with other products, like the SunVault solar battery.
Backed by a standout warranty
SunPower solar panels come with one of the longest and most comprehensive warranties on the market. The 25-year Complete Confidence warranty covers not just panels but inverters and racking equipment, too. The warranty guarantees panel production of at least 85%–92% of their original output by the end of the term.
Good for those with space constraints
More efficient panels mean you can install fewer panels on your roof for a sleeker look. If you have a smaller roof or just want to minimize the number of panels you need for aesthetic reasons, SunPower could be the way to go.
You can find comparable panels at a lower cost
As we mentioned, Maxeon now sells to other residential installers—and they have a cheaper price per watt on the EnergySage Marketplace.
SunPower's Maxeon solar panels are the most efficient on the market, but more affordable brands like REC Group and QCELLS aren’t too far behind. Looking at the table above, REC Group actually has SunPower beat on temperature coefficient and is the cheapest option of the three. Depending on your goals and circumstances, the efficiency perk may not be enough to justify the price.
SunPower’s shifting dynamics
SunPower has been evolving as a business in recent years and has hit a few bumps along the way.
SunPower officially split from Maxeon in 2020 but maintained an exclusive partnership until March 2024. Under that agreement, SunPower branded and installed all Maxeon and Performance solar panels. Unfortunately for SunPower, those supply agreements were terminated, meaning Maxeon is free to sell its high-efficiency solar panels elsewhere.
A month after SunPower lost its exclusivity with Maxeon, the company announced it was leaving residential direct sales. Instead of working directly with SunPower to install solar panels on your home, you’ll now go through a third-party. This announcement included other key business decisions made to boost financial viability.
With limited public information available, it’s unclear how this will affect your customer experience. SunPower has 40 years of reputable experience as a company, but it’s important to keep these recent bumps in mind as you shop.
SunPower’s customer service receives mixed reviews
SunPower has 4.5 out of 5 stars on EnergySage based on over 560 reviews, which shows that most people seem pleased with their SunPower installations. But, of the negative reviews, most cite poor customer service and difficulty remedying warranty claims as the reason for their dissatisfaction. Similar testaments can be found on Yelp and Reddit.
This isn’t to say that you shouldn’t go with SunPower because of these negative reviews. They’ve received more positive than negative ratings. But, there does seem to be a common theme in the negative reviews they have received. It’s just something to keep in mind and ask your SunPower representative about!
There’s no denying SunPower’s status as an industry veteran. The SunPower Equinox Home Solar System is a comprehensive, sleek, and effective option for those prioritizing performance. Moreover, SunPower systems have a robust warranty that seals the deal for many solar shoppers. But SunPower isn’t a manufacturer anymore. You can install Maxeon solar panels without going through SunPower, and it may be cheaper to do so.
- 100% free to use, 100% online
- Access the lowest prices from installers near you
- Unbiased Energy Advisors ready to help
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