Sunpower Solar Panel Review


Jack Ayre

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Sunpower is an excellent solar brand who are well respected in the industry – so you’ll probably come into this review with some idea about how it’s going to go. That’s right, Sunpower solar panels are great. There’s no surprise there. But by reading the review below we hope you’ll be able to determine whether Sunpower solar panels are right for you and your home. 

Sunpower In Brief:

Sunpower prides itself on being one of the oldest solar companies in the United States of America. The solar technology provider is known for developing and manufacturing: AC panels, micro inverters, batteries, and other key solar technologies. However, the company made its name through the engineering, financing, constructing, and maintenance of solar power plants which use solar panels to generate electricity.

Having manufactured a selection of the world’s most efficient solar panels, it is easy to understand why Sunpower is a popular choice amongst customers. Not only has Sunpower received over 1,000 patents for solar innovation, but it’s panels have almost 23% efficiency, which is higher than the standard average.

Included in the company’s portfolio, Sunpower currently offers four solar panel lines including the: M Series, A Series, X Series, and E Series, with each line featuring an efficiency rating of 20% or more.

Sunpower Company Overview:

Sunpower’s journey dates back to the 1970s when the company’s co-founder, Dr. Richard Swanson, started to investigate alternative methods to solve the oil crisis. Inspired by solar cells used in the manufacturing of satellites, Swanson started to research ways that allowed him to make cost-effective solar cells.

In the mid-2000s, Sunpower started its shift to residential solar production with its acquisition of PowerLight. This move was further cemented in 2016, when SunPower launched its SunPower Equinox system which claims to be the first residential solar solution in the United States of America.

Since then, Sunpower has continued to grow within the residential solar energy market. Due to its longevity, Sunpower has established itself as an industry leader within the solar sustainability market, and has gained a reputation regarding its positive social responsibility ethos. The company also prides itself on being the only solar company based in the USA that has been around longer than 25 years.

Sunpower solar panels

Sunpower Solar Specifications:

The Maxeon 6 AC Solar Panel series by Sunpower was manufactured to optimise three specific areas. These are:

  • Efficiency: By enhancing the solar panel’s performance levels in high temperatures as well as optimising energy conversion levels in low-light conditions, the Maxeon 6 AC Solar Panel series maximises its ability to generate energy and power. This makes this range a solid choice for residents living in areas where cloudy days are the norm. Additionally, these solar panels will generate the maximum amount of electricity during those low performing hours in the morning and evening.
  • Reliability: Featuring crack-resistant cells and reinforced connections which aim to minimise fatigue and corrosion, Sunpower claims this solar panel series can survive all types of weather conditions. With the addition of micro inverters, the solar panels in the Maxeon 6 series have independent panel operation. Meaning that if some solar panels are being impacted by shade or are faulty, those that aren’t will still be able to function like normal.
  • Sustainability: Sunpower claims that its solar panels, as well as other solar technologies they produce, are manufactured responsibly using clean ingredients. The company also states that its solar panels can produce energy for up to 40 years.


In addition to these three key factors, Sunpower is well-known for its substantial warranty scheme. The Maxeon 6 AC Solar Panels will feature a 40-year warranty, with the micro inverters included in the series covered for 25 years (by Enphase).

The Maxeon 6 AC Solar Panel series features two variations with differing wattage power. These are the SPR-MAX6-425-BLK-E4-AC and the SPR-MAX6-415-BLK-E4-AC. 


By combining its renowned Maxeon technology with one of Enphase Energy’s most advanced inverters, the Maxeon 6 AC Solar Panel series is said to be one of the most efficient solar products in the industry. The 425 W version of the series provides customers with the ability to get the most out of the product.

The higher wattage variety of the series provides a higher module efficiency rating than its smaller counterpart at 22.0%. Additionally, it has a higher nominal power wattage, which stands at 425 W. Both models withstand a maximum load of:

  • Wind: 3600 Pa, 367 kg/m² back.
  • Snow: 5400 Pa, 551 kg/m² front.


Which is an improvement on its predecessor, the Maxeon 5 AC series. However, a bonus of the SPR-MAX6-425-BLK-E4-AC is that the previous Maxeon 5 series did not feature a variant with 425 W capabilities. 

Nominal power (Pnow)425 W
Module efficiency22.0%
Warranties40-year limited power warranty

40-year limited product warranty



Unlike its counterpart, the SPR-MAX6-415-BLK-E4-AC model can be directly compared to the SPR-MAX5-415-E3-AC variant from the Maxeon 5 AC series. While the more recent model takes a 0.7% dip in efficiency, the SPR-MAX6-415 has a 15 year longer warranty for both power and product. Additionally, the newer model can also withstand poorer weather conditions compared to its predecessor.

The main difference between the SPR-MAX6-415 and the SPR-MAX6-425 models is their power wattage. The 10 W difference will go on to impact three primary areas, these are:

  • The cost of your solar panels: With a lower wattage, the SPR-MAX6-415 is set to be cheaper than its counterpart.
  • Efficiency levels: The SPR-MAX6-425 has a 0.5% efficiency improvement compared to the smaller model.
  • Size: If you have a smaller roof, or a limited amount of space, then the SPR-MAX5-415 will be perfect for you. This variant is smaller than its counterpart, but with only marginal differences when it comes to power.


Nominal power (Pnow)415 W
Module efficiency21.5%
Warranties40-year limited power warranty

40-year limited product warranty


Sunpower Solar Panels Pros And Cons

  • Sunpower’s solar panels have higher power outputs compared to its competitors.
  • Sunpower’s solar panels are considered to be some of the most expensive on the market.
  • The brand has a well-established reputation for reliability and efficiency.
  • Expensive solar panels will often lead to a higher outlay.
  • Sunpower products come with some of the longest warranties in the industry, with the Maxeon 6 series featuring a 40-year warranty.
  • The Maxeon 6 series solar panels have an approximate life expectancy of 40 years.
  • Sunpower’s latest range has boosted durability levels, with the panels expected to survive the harshest conditions. Especially relating to wind and snow.
  • The Maxeon 6 series uses Enphase Energy’s most advanced inverter.


Sunpower FAQs

Q: When was Sunpower first established?

Sunpower is considered to be one of the oldest solar energy companies in the United States of America. The company started operating in 1985, however the creation of Sunpower dates back to the 1970s with the company’s co-founder Dr. Richard Swanson.

Today, the company operates out of Silicon Valley in San Jose, California. Although Sunpower is based in the United States, the company’s solar products are available in over 100 countries across the globe. 

Q: What variety of solar panels does Sunpower install?

Sunpower exclusively sells and installs Maxeon solar panels. In 2020, Maxeon became a spin-off company of SunPower. However the two retain a close relationship, which is highlighted by this exclusive deal.

Q: What is the difference between Sunpower solar panels and conventional panels?

The Maxeon solar panels used by Sunpower are industry leading and feature a host of benefits that securely put them above other manufactured solar panels. These benefits includes:

  • Improved efficiency: Maxeon solar panels generate more electricity compared to other solar panel brands. Sunpower’s Maxeon 6 series was the first solar panel in the European and Australian market to feature a 400 W variant. At the time, other competitors’ solar panels were rated between 280 and 310 watts.
  • More cost-effective: Sunpower’s solar panels claim to generate more solar power both in the short-term and long-term, while also taking up the same amount of roof space as its competitors. Meaning customers will get more electricity for their money, allowing them to be more self-sufficient.
  • Lower degradation rating: The standard degradation rate for other conventional solar panels on the market stands at around 0.75% a year. Meanwhile, Maxeon’s solar panels have an estimated degradation rate of 0.2% a year. This will result in a boosted lifespan for the Maxeon panels compared to its competitors.
  • Industry leading warranty: One of Sunpower’s biggest selling points is the length of its warranty when it comes to the company’s Maxeon solar panels. Sunpower’s 40-year warranty is the longest available warranty for this type of product in the industry, which provides customers with greater peace of mind when they opt to purchase one of Sunpower’s products.
  • Social responsibility: Sunpower has always promoted social responsibility as part of its company’s ethos. In line with their beliefs, they were the first company to disclose the ingredients used during the manufacturing of its solar panels. They also pride themselves on using clean ingredients during the responsible manufacturing of its products. Additionally, the company’s Mexicali manufacturing facility has received the NSF Sustainability certificate for Zero Waste to Landfill. This means that 99% of the facility’s waste is diverted with less than 1% going to landfill.


Q: What are the power benefits of using Sunpower’s solar panels?

Compared to conventional solar panels, Sunpower’s Maxeon panels aim to deliver up to 25% more energy. This advantage grows to up to 45% during the solar panel’s 25th year of operation. With the Maxeon panel’s predicted lifespan of 40 years, this will grow into a substantial power advantage.

Q: How much does Sunpower’s solar panels cost?

There are many variables that can impact the final price of your solar panels. These include:

  • The wattage of the solar panels.
  • The size or amount of solar panels you require.
  • Additional transportation and installation costs.


Due to these variables, there is no set price regarding how much solar panels may cost you. However, you tend to get what you pay for. The more money you are willing to spend on your solar panels, the better quality product you will receive. Factors like reliability, efficiency, and durability will be improved with a higher-spec and more expensive solar panel. With Sunpower’s solar panels, you may need to spend more money up front, however you will save more money on your energy bills in the long run.

Q: How do you get Sunpower’s 40-year warranty?

As we have previously mentioned, Sunpower’s Maxeon products have a 40-year warranty. This is not a typical warranty length within the industry, and should be considered a major benefit of choosing Sunpower when purchasing your solar panels.

However, to claim the 40-year warranty you must register your Sunpower Maxeon solar panels within the six months of your warranty start date. If you fail to do this, you will be stuck with the 25-year Sunpower warranty instead.

Q: What inverter does the Maxeon 6 range use?

The Sunpower Maxeon 6 series features Enphase micro inverters. The presence of these micro inverters allows each solar panel to work individually, meaning if one panel is shaded or has a technical fault, the rest will still work as normal. 

While the Maxeon panels themselves are considered to be industry-leading, Enphase’s inverters should help your solar panel system generate around 50% more energy compared to a conventional solar panel system over its predicted 40-year lifespan. Additionally, Enphase’s inverters come with their own warranty package of 25 years.

Q: How long does Sunpower’s solar panels last?

The typical expected lifespan of solar panels is approximately 25 to 30 years. However, Sunpower claims that its Maxeon 6 solar panel range could last up to 40 years. Such a feat is made possible with Sunpower’s Maxeon 40-year warranty policy, as customer’s will be able to get their solar panel systems serviced for a longer period of time. Not only does this make Sunpower’s Maxeon 6 range more cost-effective as it will last for a longer period of time, but it also boosts the sustainability of the solar panels themselves.

Q: Are Sunpower’s solar panels worth it?

If you are considering purchasing Sunpower’s solar panels but are being turned off by the price, then you should ask yourself the following questions to see whether the purchase will be worth it for your household.

  • What is your household’s current energy usage? Sunpower’s solar panel systems are very powerful and are perfect for households that use a larger amount of electricity. If your family is either small or very energy efficient, then perhaps the Maxeon 6 range will not be cost-effective for you.
  • How much available roof space do you have? No matter what solar panel manufacturer you are opting to go with, you should always consider the amount of roof space you have available. The smaller the amount of roof space you have, the more efficient you will require your solar panel system to be as you will have less solar panels available to generate energy.
  • Have you looked into financing options? If you have your heart set on purchasing from Sunpower, but are worried about the costs, have you checked out different financing options that may be available. Depending on your installer or the manufacturer of the solar panels you choose, this could mean: paying nothing upfront, flexible payment plans, faster application process times, higher credit limits, and lower monthly payment plans. 


Sunpower Solar Panel Review Summary

If you are looking for efficient, reliable, and sustainable solar panels that will provide you with a greater peace of mind, then look no further than Sunpower’s Maxeon 6 AC Solar Panels. The series features two variations: the SPR-MAX6-425-BLK-E4-AC and the SPR-MAX6-415-BLK-E4-AC.

Compared to previous Maxeon solar panels, this new series features improved efficiency levels, with the panels set to optimise the amount of energy they generate even in low-light conditions. Additionally, they also feature increased reliability levels with crack-resistant cells and reinforced connections to help protect against fatigue and corrosion. 

The Maxeon 6 series is also protected by Sunpower’s 40-year warranty (upon registration), furthering the sustainability levels of the solar panels which are also responsibly manufactured using clean ingredients.

As one of the longest standing solar companies in the United States of America, with almost 40 years of experience, their high quality standards and reliable reputation precede them. If you are looking to maximise the solar energy your household can generate, and want to purchase from a brand you can trust, then look no further than Sunpower’s Maxeon 6 AC Solar Panel range. If you require further help, or have more questions about the solar panel that’s best for you, then get in touch with us today, we are more than happy to help!

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Born in North West England, Jack kicked off his career in the insurance arena, dealing with claims for three years. Always up for a challenge, Jack leapt out of his comfort zone and embarked upon 5 years of excitement with the military.

Working for the Ministry of Defence, Jack specialised in counter-terrorism which took him to places such as Dubai, Oman, Iraq, Norway and Bahrain. During this period he worked with various Governments implementing strategic operations to prevent terrorism.

After travelling around various countries Jack increasingly came across various forms of solar from large solar farms to domestic solar panels. From here Jack took a keen interest in all things solar and started reading about the technological capabilities with a view to entering the industry after his career in the Ministry of Defence.

Once home after 5 fruitful years, Jack had 3 months leave in which he immersed himself in a solar crash course and got applying for jobs within the solar sector. He came across ESE Solar, a long-established forward-thinking company whose head office was only a stone’s throw away from him. He picked up the phone to see if there were any vacancies and within a week had a successful interview and obtained a full-time job, starting in the technical team.

Within the first few months, Jack onboarded in various online courses during work and social hours to speed up his knowledge of all things solar. Due to his strong work ethic and thirst for knowledge Jack was promoted to Head of Technical at ESE Solar. He currently leads the team and oversees the product development of new technologies within the company alongside assisting where necessary on their maintenance department.

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