sunpower solar panels review

SunPower was one of the first companies to produce solar products, and their panels continue to be some of the best-performing and most efficient ones on the market.

In this SunPower solar panels review, we’ll look at some of their stand-out products and the benefits and advantages of their solar panels and cells.

SunPower solar panels review: the best panels and cells

SunPower offers a range of rigid and flexible solar panels of various sizes, as well as individual solar cells. Here are our top picks for some of their best products.

1. SunPower 50 Watt Flexible Monocrystalline Solar Panel

This flexible solar panel is made with Maxeon Generation III mono-crystalline cells that offer 23.5% efficiency, more than most comparable flexible panels. This allows you to get the maximum amount of energy from the compact panel.

Weighing just 2.5 lbs, this small, light panel is highly portable. You can easily take it with you when camping, RVing, or use it as a backup charger for your vehicle.

It comes with pre-drilled holes for easy installation, so you can mount it on your boat, RV, or cabin and then use it elsewhere as required.

The compact panel is not super powerful, with just 50 watts of output, but is sufficient to charge your devices. You could also hook together two or more of these panels in a series to generate more electricity.

This solar panel is also highly durable and will stand up to all kinds of weather conditions, making it suitable for various applications. Its built-in micro junction box is rated IP67 waterproof, making it ideal for outdoor activities and boating.

However, some online reviewers complain that the MC4 connection is difficult to disconnect – unlike some other panels, you cannot simply pull out the link by hand, so you need to have the appropriate tool with you whenever you want to uninstall the panel.

The panel comes with a two-year product warranty, five-year power warranty, and a 25-year materials and workmanship warranty backed up with SunPower’s customer service.

What we like:

  • Portable: Lightweight and compact, you can take this panel with you boating, hiking, or on canoe trips.
  • User-friendly: Easy to install and use, the panel is ideal for beginners.
  • Highly efficient: With a conversion rate of 23.5%, you’ll get the maximum amount of energy from the sun available, which is great for low light conditions.

What we don’t like:

  • Difficult to uninstall: Though easy to set up and install, the MC4 connectors cannot be disconnected by hand, making the panel a bit tricky to uninstall.

Although not the most powerful solar panel on the market, this high-efficient, lightweight, and robust flexible solar panel is a great pick for anyone looking for a portable power source for their outdoor activities.

2. SunPower 110 Watt Flexible Solar Panel

This flexible panel is a more powerful option, offering up to 110 watts of output. This makes it suitable for charging multiple devices or running simple appliances such as a mini-fridge.

Like SunPower’s 50-watt flexible solar panel, it is highly-efficient, well made from lightweight polymer materials, and highly durable. The panel is relatively-small and light, weighing 4.4 pounds and measuring 46 x 22 x 0.8 inches, so is great for small roof spaces and vehicles.

With a robust frame, you could also take the panel with you on camping trips, or use it for temporary installations. It’s flexible, and can be bent up 30 degrees, meaning you can wrap it to fit your boat or RV roof, or install it on curved awnings or roof spaces.

In the unlikely event that you have any issues with the panel, you’re covered by SunPower’s excellent warranty periods. Unlike some other manufacturers, the warranty isn’t impacted if you expose the panel to salt water, so you can confidently use it on your boat or canoe trips without compromising security.

What we like:

  • Flexible: You can bend this flexible panel up to 30 degrees, making it suitable for curved roofs, RVs, and boats.
  • Durable: The robust panel comes with a sturdy frame, so it will stand up to all kinds of weather conditions, and you can transport it without it getting damaged.
  • Excellent warranty: The panel comes with extended warranties, so in the unlikely event you have any problems, you’ll be able to get a replacement from SunPower.

What we don’t like:

  • Less portable: Larger and heavier than the 50-watt version, you may be better off opting for the small panel depending on your power needs if portability is important to you.

Though not highly portable, this 100-watt solar panel offers more power while still being compact and lightweight, making it a great solution for boats, RVs, and cabins.

Take a look at our round-up review of the best flexible solar panels for more options.

3. SunPower Flexible Solar Cells for DIY Panels

These DIY solar cells let you build your own panel to your own custom specifications.

Each cell is a flexible mono-crystalline solar cell made with patented USA technology to make it highly efficient. This means that your DIY panel will be able to convert the maximum amount of sunlight into energy.

The cells are also designed to perform well in partial shade and low light conditions, by sending the current through shaded cells in the same series. This means that it will produce a consistent amount of energy even if parts of the panel pass into the shade and also gives you the flexibility to avoid using diodes if you choose.

These cells produce twice the amount of voltage as traditional wafer cells, meaning you can use them to create powerful, highly-efficient cells that generate more power with a smaller footprint.

The set comes with 500 cells, with +2 bushbars per cell. The cells are super thin, light, and flexible, so you can use them to make flexible panels suitable for curved spaces such as awnings, boats, or vehicle roofs.

Each cell comes with three solder points per polarity, making them easy to assemble.

However, it should be noted that these cells are not for beginners. Unlike SunPower’s flexible solar panels, these individual cells do not come with a protective edge and being flexible doesn’t make these cells less fragile or simple to work with.

Online reviewers complain that the cells are fragile and easy to break, though this could be said of virtually any solar cell, and other users note that they are more robust than solar cells from other brands. 

Unless you have some knowledge of putting together a solar panel and are prepared to handle the cells with plenty of care, you’re probably better going for a more ready-made solution.

What we like:

  • Highly efficient: This is only of the most advanced, efficient consumer solar cells available, so is perfect for building custom solar panels that will give you the maximum power output for the footprint.
  • Flexible: Being flexible cells, you can use them to build panels for curved surfaces, making them ideal for RVs, boats, and curved roofs.
  • Easy to assemble: The cells come with pre-installed solder points, making them relatively easy to assemble for people with the necessary skills and tools.

What we don’t like:

  • Not user-friendly: You’ll need to handle these cells with care to avoid breakages, and it’s best to only try to build your own solar panel if you have a certain level of knowledge and experience.

Though not the best solution for everyone, SunPower’s flexible solar cells are great for experts who want to build their own custom, flexible solar panels.

What is SunPower?

Founded in 1985, SunPower is one of the world’s oldest manufacturers of solar panels. The renowned USA-based energy company makes a range of silicon photovoltaic cells, solar panels, and solar power systems for both residential and commercial use.

Majority-owned by Total SA, the company started in the USA and has since expanded its operations across the country and established facilities in Europe, Asia, and Mexico.

sunpower solar panel review

The brand is known for quality products and highly-efficient solar cells. These have some of the highest conversion rates on the market, at between 22 and 25% (compared to 14% to 18% for most flexible solar panels).

SunPower panels are also built to last, with lower degradation and longer-lasting performance than many competitors. This is evidenced by the impressive warranty they offer for their products, with a standard two-year product warranty and a five-year power warranty.

Another testimony to the quality and reliability of SunPower’s PV cells is their high-profile clients, who include NASA and Honda, who used their panels on their winning solar challenge car.

SunPower solar panel series

SunPower produces solar panels for both commercial and residential applications, and currently, they have three product series: their M, X, and U-series panels.

The key features of each series are:

  • M-series: Extremely efficient and powerful AC-solar panels for home solar systems, loaded with 104 solar cells ranging from 420-440 watts. This series is ideal for medium to larger homes with extensive solar systems, including those seeking to go entirely off-grid.
  • X-series: For residential and commercial use, these panels are designed to be highly efficient so that you can get maximum power with fewer panels on your roof, so is perfect for smaller homes. The model numbers of this series give you a clear picture of the efficiency of each product: for example, their X22 has an efficiency of 22.1%.
  • U-series: The latest series of SunPower products, the U-series aims to provide complete home solar solutions with built-in micro-inverters that you can connect to the SunPower app on your smart device. The panels also have a streamlined appearance to make them less visible on your roof.

Are SunPower solar panels any good?

If you’re planning to buy a solar panel for your home or office this year, read this section carefully. We’ll disclose all the SunPower pros and possible cons that will help you make a better decision.

So let’s get to know about them one by one.

Benefits of SunPower solar panels

SunPower solar panels are well-made and offer a range of advantages.

1. They use high-efficiency IBC cells

SunPower introduced interdigitated back-contact cells (IBC) in 2007, and they remain one of the market’s most efficient types of solar cells. SunPower’s panels receive overwhelmingly positive reviews, primarily due to their high-performance IBC cells.

A 3-D view of SunPower's Maxeon IBC technology
Source: SunPower

A key advantage of SunPower’s IBC cells is that they feature a diffusion layer, allowing the manufacturer to install metal contacts and other structural elements on the back of the cells. This means that there’s nothing on the front of the cell that could block sunlight and make the cell less efficient.

This makes SunPower’s solar panels highly efficient, with conversion rates between 22% and 25% compared to 14% to 18% for cheaper products.

These cells also boast a low degradation rate, so they’ll continue to perform well for years. You can keep using your panel without the efficiency dropping off, representing significant long-term savings on energy bills and equipment replacement.

2. They perform well in all conditions

Most solar panels perform best when in relatively-cool conditions, preferably below 25°F. For every degree above this, a standard solar panel’s power capacity can drop by up to 0.3%.

This can obviously be pretty problematic for a piece of equipment that’s designed to work in the sun on a hot roof!

However, SunPower panels are designed to perform well in all weather conditions, even under warm temperatures. The brand’s products have an excellent temperature coefficient rating of 0.29, signifying that they’ll deliver the same level of performance no matter the temperatures and conditions they’re exposed to.

This means that you’ll get the most out of your solar panels every day of the year and be able to harvest the maximum amount of solar energy on hot, sunny days. Furthermore, if you connect your SunPower panel to a battery, you can store this energy for later and use the sun’s power to run your devices when it’s cloudy or even overnight.

3. Excellent warranty periods

SunPower also offers excellent warranty periods, with a two-year power warranty and five-year product warranty standard on their residential, commercial, and portable solar panels. Better still, all the brand’s products are covered for workmanship and material defects up to 25 years, compared to a 10-year period offered by many competitors.

Not only is this an indication of the quality and reliability of their products, but it means you’ll enjoy the extra peace of mind of knowing that they’ll address any issues you may have. The company also offers good customer service and technical support.

4. They’re highly versatile

SunPower is one of the few solar manufacturers that offer consumer PV cells that you can use to build your own solar panels. If you have a certain level of expertise, you can custom-make your own solar panel to your specifications.

Regarding their ready-made products, the brand also has a wide range of panels to suit various purposes, from powerful panels for home solar systems to flexible and portable panels which are suitable for everything from camping and canoeing to installing on your boat or RV.

Drawbacks of SunPower products

Although SunPower’s panels and solar cells have a range of benefits for residential and commercial users, they also have a few drawbacks you should be aware of.

1. They’re more expensive than many alternatives

SunPower’s solar panels and solar cells are premium products and they come with the corresponding price tag. Their products do involve a significant upfront cost, and you may be scared off by their prices which can be much higher than seemingly-comparable products.

Furthermore, to build a solar system, you’ll also need to invest in other equipment, such as a solar charge controller, inverter, and battery to store your energy. SunPower focuses on solar panels and cells, so you’ll need to source this equipment from another brand.

SunPower solar inverter
Source: SunPower

On the other hand, this is a one-time investment that will likely pay for itself over time by reducing your reliance on the grid and slashing your energy bills. Moreover, these excellent panels will continue to perform well for years and come with an extended warranty.

Therefore, going for a cheaper solar panel could be a false economy, as you may need to replace it sooner and end up spending more in the long run. Additionally, lower-quality products deteriorate more quickly and lose efficiency, minimizing your energy savings.

2. Limited buying options

Although SunPower is one of the US’ biggest solar manufacturers, their products could be much easier to find. Only a limited number of SunPower panels are available on Amazon, including the SunPower 50 Watt Flexible Monocrystalline Solar Panel and SunPower 110 Watt Flexible Solar Panel; not all solar panel dealers stock their products.

This means that you may have to hunt around to find the SunPower product you want, making it difficult to compare prices and get the best deal.

3. DIY solar panels are more difficult than you think

Thanks to the customization options, you may be tempted to build your own solar panel using SunPower’s solar cells, not to mention the potential savings of DIY panels. However, it’s essential to remember that this is a complex project.

a woman holding SunPower solar cells
Source: SunPower

Even though their SunPower Flexible Solar Cells for DIY Panels are flexible and robust, like all solar cells, they are fragile and can easily break as you work with them.

Therefore, breakages may mean you spend more on your DIY solar panel than buying a ready-made product. It’s best to only attempt this if you have the required level of expertise, not to mention patience.

Is SunPower the best solar panel provider?

SunPower is one of the world’s oldest manufacturers of solar panels and cells, which offers a range of high-quality, durable, and versatile products backed up by excellent warranty periods. Most notably, their solar products are highly-efficient, offering some of the best conversion rates currently available.

However, any SunPower solar panels review would be incomplete without acknowledging the issues with the brand, most notably the high price tag that comes with their products. Having said that, the high upfront investment is balanced with the excellent performance and efficiency of these products over the long term, not to mention that they will last longer.

Want to learn more about the best solar products? Take a look at our guides to the best flexible solar panels, ground-mount solar systems, and off-grid solar kits.

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