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Sunpower is one of the oldest American solar companies out there. Its solar panels have powered NASA aircraft and racecars and the company’s solar panels have produced over 18 million MWh of electricity.

Today, Sunpower is majority owned by French oil and gas giant Total and is best known for its ultra-high efficiency solar panels, which currently hold the world record for most efficient rooftop panel.

As of 2021, those efficiencies are hovering around 23%, compared to about 18% for the average solar panel. With that high efficiency though also comes a higher cost.

Editors Tip: To make sure Sunpower panels are right for your home, we always recommend getting more information from solar panel experts via UnderstandSolarPower. They can quickly and easily help you determine which solar panel is best for your home without a lot of fuss.

Read on to read our in-depth review of Sunpower solar panels and how they compare to the competition.

sunpower solar panels
Image Source: Sunpower

How Sunpower Solar Panels Compare to the Competition in 2021

Sunpower vs Panasonic

Sunpower panels are the most efficient rooftop solar panels available today, but efficiency isn’t the only factor to consider when looking at solar panels. Of equal importance are:

  • Durability: If the panels begin to degrade and die after just five years, does it really doesn’t matter how efficient they are?
  • Warranty: Things happen and it’s reassuring to know you have options.
  • Availability: It could be the best solar panel in the world, but if it’s not available, does it even matter? (We’re looking at you, Tesla roof shingles)
  • Company Health: You might have an industry-leading 25-Year warranty, but if the company goes under, you’ll be out of luck.

Let’s break down Sunpower’s products in each of these categories. For greater context on how Sunpower compares to other solar panels, we’ll compare the specs of Sunpower against two other solar manufacturers: JinkoSolar and Panasonic.

JinkoSolar is the largest solar panel manufacturer in the world and produces quality, if ‘standard’ solar panels with average efficiency and warranties. Panasonic, like Sunpower, is a premium brand that manufacturers high-quality solar panels with long-term warranties, but also suffers high prices. Tesla uses Panasonic solar cells in its own solar panels.


Winner: Sunpower

Efficiency measures the amount of sunlight the solar panel can convert into usable electricity, as a percentage of all sunlight that hits the panel.

As of mid-2019, Sunpower manufactures the most efficient residential solar panels on the market, beating out rivals Panasonic, LG, and REC Solar. Its most efficient panels, the X-Series, boast a 22.8% efficiency.

Pansonic’s HIT series of panels, which Tesla uses for its own solar panels, are 19.7% efficient. While still more efficient that ‘standard’ panels, that’s a far cry from Sunpower. While a difference of 3.1 percentage points might not sound like much, at this rate the Sunpower X-Series can actually produce almost 16% more electricity than Panasonic’s panels, which means you’ll see a faster return on your investment with Sunpower, as your installation will pump out more energy per panel.

While JinkoSolar’s top-of-the-line residential solar panels, the Eagle line, boast up to 20.08% efficiency, its workhorse residential panels – the Eagle series – are just 16.2% to 17.4% efficient (depending on the wattage). On the lowest end of the spectrum, that’s about 30% less than Sunpower X-Series panels.

Of course, efficiency is just part of the equation when working out the value of a solar installation. The cost of the solar panels must also be taken into account, which we dive into below.


Winner: Sunpower

Solar panels will be up on your roof for 25 years or more, so you need to know that they’re up to the task of the extreme heat (roofs can get up to 150F in the summer!), strong winds, pouring rains, freezing ice, and layers of heavy snow.

All solar panels must meet minimum wind loads and snow loads. Generally, solar panels can handle 5,400 Pascals (equal to 113 pounds per square foot) of snow and 2400Pa of wind. Anything above that is extra credit and there are few companies, including Sunpower, that spend the time and money to get there.

While both Panasonic and JinkoSolar meet just the minimum requirements, Sunpower goes above and beyond, with its solar panels handling 6000Pa of snow and 3000Pa of wind. Here’s how the stats work out:

  • Sunpower: 6000Pa snow load, 3000Pa wind load, –40° F to +185° F operating temp, 1” hail at 52mph
  • Panasonic: 5400Pa snow load, wind unknown, -40°F to 185°F operating temp, 1” hail at 52mph
  • JinkoSolar: 5400Pa snow load, 2400Pa wind load, -40°F to 185°F operating temp, hail unknown

If you live in an area with extreme weather – hail, heavy snow, and blistering heat – certainly consider installing solar panels that can better handle these weather swings. Sunpower panels can, but they’re also expensive. Canadian Solar also makes panels that can handle higher snow and wind loads, at a much lower price point. The company’s Standard series can handle 6000Pa of snow and 4000Pa of wind – even better than Sunpower’s panels – and solar installers find them to be a good balance between durability and cost.


Winner: Sunpower

Hands down, Sunpower has some of the best – if not the best – warranties in the entire solar industry, beating out other premium products like Panasonic. Sunpower warranties are long lasting and prove the company believes their solar panels are the most durable on the market.

Solar panel manufacturers typically offer two warranties: product warranties and production guarantees.

Product warranties are just like any other warranty. If something breaks or stops working, the company will either fix or replace it. It’s the same as your car or smartphone warranty. Most ‘standard’ solar panels offer a 12-year product warranty, though that can range from 10 years for cheaper products up to 25 years for the high-quality models.

Sunpower offers 25-year product warranties for its solar panels. JinkoSolar offers 12-year product warranties, while Panasonic also offers 25-year warranties.

Production guarantees, on the other hand, are unique to solar panels. These protect against long-term efficiency loss in the solar panels. Production guarantees almost always last 25 years regardless of the manufacturer, but exactly what they guarantee varies. The best manufacturers offer a 25-year guarantee that the solar panels will produce 87% or more of their nameplate capacity (in other words, the wattage listed on the back of the panel). As the cost goes down, so does this percentage. The cheaper-end panels drop down to guarantees around 80%.

Sunpower guarantees that its solar panels will produce 92% of their nameplate rating in Year 25. Again, this is one of the highest in the industry. Panasonic guarantees their solar panels will produce 90.76% by Year 25, while JinkoSolar ensures 80.7% to 81.55% efficiency by Year 25, depending on the solar tech used.


Winner: JinkoSolar, Panasonic

In availability, Sunpower is far different from the other solar panel manufacturers. Solar panels from both Jinko and Panasonic are freely available on the market. Though you might not know how to install them, you’re free to go to an online retailer and buy solar panels from either company.

If you really want Jinko or Panasonic solar panels, any installer can simply buy them through a distributor.

Sunpower though is different. It doesn’t sell its solar panels to just anyone. Instead, it only works with pre-approved installers and it actually places its partner-installers in a three-tier system:

  1. Authorized Dealers must complete training and meet performance standards. This is the lowest tier
  2. Elite Dealers have completed advanced training and meet more stringent performance standards
  3. Master Dealers are invitation-only and act as local representatives for Sunpower

If you want to install Sunpower panels, you’ll need to go through one of the company’s pre-approved solar installers. This could be problematic, as some states don’t have any pre-approved installers. If you live in California – ground zero for solar in the US – you’ve got a wide net of Sunpower-approved installers, but in other areas your pool of potential installers is vastly limited. In Denver, for example, where solar is plentiful, there’s only two Sunpower-approved installers. This greatly limits your pool of potential installers, and could lead to paying more, as there’s less competition.

Company Health

Winner: Panasonic

As we mentioned, your solar panels will be on your roof for 25 years or more. While the solar industry has calmed down since its Wild West years a decade ago, a time when solar businesses were going under left and right, it’s still a roller coaster of an industry. No matter the manufacturer, you want to know your solar panel company is going to be around long enough to make good on any warranty claims.

Truly assessing a company’s health is beyond the scope of this short article, but we can take a quick dive to get a feel for how the above three businesses are doing by looking at each company’s profit margin, or its net income after subtracting expenses and taxes compared to its revenue. Let’s compare (numbers current as of July 2019):

  • Sunpower: Net profit margin of -46.65%
  • Panasonic: Net profit margin of 3.66%
  • JinkoSolar: Operating profit margin of 1.68%

All of these margins would be considered low by most standards, but Sunpower’s really stands out as pretty dismal. With a profit margin of just under -47%, for every dollar that Sunpower makes, it’s losing forty-seven cents. In other words, they’ve got a hole in their boat – and a big one at that. In the first quarter of 2019, it reported a net loss of $89.7 million.

Sunpower hopes to turn around their profitability as the solar industry grows, but compared to the other two panel manufacturers, it’s got a much longer, harder road to travel.

How Much Do Sunpower Solar Panels Cost?

Remember how we said that you can’t buy Sunpower solar panels online? Unfortunately, that throws a wrench in estimating solar panel costs, as cost details simply aren’t available as for JinkoSolar or Panasonic.

Anecdotally, we’ve found that Sunpower panels cost about 2x as much as ‘average’ solar panels. NREL estimates that small, local installers pay about $0.76 per watt for ‘average’ solar panels, so we can expect Sunpower’s panels to cost about $1.50 per watt.

Needless to say, that’s on the high end of the price spectrum. Let’s compare the estimated price of Sunpower panels to solar panels from Panasonic and JinkoSolar, as well how much you’d spend to build a 6 kilowatt solar installation.

  • Average-quality panel: $0.76/watt; $4,560 for 6kW
  • Sunpower: $1.52/watt; $9,120 for 6kW
  • Panasonic: $1.12/watt; $6,720 for 6kW
  • JinksoSolar: $0.69/watt; $4,140 for 6kW

You’ll see that Panasonic comes in about forty cents lower than Sunpower and JinkoSolar’s prices are less than half of Sunpower’s costs. For an average-sized 6 kW solar installation, you’d pay a premium of about $4,500 for the Sunpower panels.

Of course, the solar panels are just a part of your installation costs. You’ll need to buy wiring, mounting hardware, and an inverter, as well as pay for labor, sales, profit, etc. Adding all this up, if you install ‘average’ solar panels, the solar panels themselves only make up about 25% of your total installation costs.

At this price, a 6kW installation, in total, would set you back about $17,940. Assuming all other installation costs stay equal, paying the premium to install Sunpower solar panels would jump that percentage up to 41% and increase your total installation cost to $22,500.

Solar is a financial investment and you want to see the fastest return on your investment. Exactly how quickly you recoup your investment depends on your location, but an extra $4,500 will likely draw out your ROI 4 to 8 years depending on both the amount of electricity your installation can produce as well as your utility rates. Whether or not the peace of mind from Sunpower’s excellent warranty is worth that hefty premium is up to you.

How to Find the Best Solar Panels for Your Home

Sunpower solar panels really are the best residential solar panels on the market today. They’re ultra-efficient, extremely durable, and come with excellent long-term warranties. However, they’re also about twice as expensive as ‘standard’ solar panels, and that might just be their downfall. Every dollar you spend installing your installation, you want to recoup as fast as possible. The more you spend upfront, the longer it’ll take you to recoup your costs via avoided utility payments. Let’s take a look at the steps to find the best solar panels for your home:

1. Know your goals – Before contacting any installers, take a minute to think about what you want from your solar panels. Do you want to see the fastest return on your investment? If so, standard-quality panels probably make the most sense. Do you want the longest, most thorough warranty you can find? If so, you can’t beat Sunpower’s 25-year product warranty. Do you want the most subtle, aesthetically-pleasing panels? Look for all black panels, like Canadian Solar’s All-Black line, and ZEP Solar’s sleek rail-less mounting hardware, which allows your panels to sit closer to the roof.

Knowing what you want from the get-go will make the whole sales process faster. However, don’t get too set on a particular model until you talk to an installer, as they’ll have a deep knowledge of the pros and cons of most panels available on the market.

2. Contact solar installers for estimates – Most of the time, solar installers have two or three solar panels they like to install (usually a standard option and premium option). Usually this is a good thing, since installers will have already done the hard work for you, finding readily-available solar panels that best balance cost and features. Different installers will focus on different manufacturers and models, so it pays to get competitive quotes to compare equipment and costs.

During your initial sales meetings, the installers will lay out the different available panels and the benefits of each one. If you want to install panels from a specific brand, it never hurts to ask if your potential installers can order them. If they are a common solar panel, it shouldn’t be an issue.

3. Compare solar panel specifications – When comparing solar panels, efficiency isn’t everything. Both cost and warranty are equally important factors to consider.

With so many different solar panel wattages out there, it can be hard to make apples-to-apples comparisons around cost. Instead of focusing on the cost per panel, figure out each panel’s $/watt cost (like in our comparisons above), as it allows you to compare the value of panels of varying wattages. For example, you’re comparing two panels of different sizes.The 320-watt panel costs $170, but the 275-watt panel costs $140. Which one is the better deal? Looking at $/watt cost, we find the larger panel costs $0.53/watt, while the smaller panel costs just $0.51/watt. In this instance, the 275-watt panel is the more cost-effective option, assuming all else equal.

Spending more money on ultra-high-efficiency panels might seem like a great idea, but it rarely pans out financially. If your home has a very small roof that can’t fit many panels, you live in an area with extreme weather changes, and you don’t mind spending more upfront, Sunpower’s solar panels could be a good option for you. However, standard-quality panels have come a long way in the last decade. They’re durable, time-tested, and cheap. With their lesser efficiency, you’ll have to install more than if you installed Sunpower panels, but their low cost usually means these standard panels will give you a quicker return on your investment – even if you have to install more.

Like cost, warranties are very easy to compare, though it’s important to remember that solar panels have two warranties: a product guarantee and a production guarantee. Product guarantees last between 10 and 25 years, while production guarantees typically guarantee your panels will produce 80% to 87% of their nameplate capacity by Year 25. Exactly what your warranty covers depends on the quality of the panel. As with any electric component, things can break and having a good, long-term warranty can save you hundreds of dollars ten or fifteen years down the line.

If you want to make an even more detailed comparison among the different models, you could also compare each panel’s temperature coefficient (a measure of how temperature affects the solar panel’s energy production) and degradation rate (how wear and tear over the years affects production). However, neither of these differ too much across models, so while important, it’s really a secondary consideration. If you live in a very hot area with scorching summers, be sure to ask your installer about both of these factors, to ensure your panel can handle the inevitable high temperatures and long-term wear.

4. Remember that solar panels are only one part of the solar ecosystem – Sure you want your panels to be as efficient as possible, but there are many other factors that can affect your production as well. Your inverter type, the placement of the panels on your roof, and even the length of your wiring all have a direct effect on your total net production.

The best installers in your area will know where to install your solar panels on your roof and how to run wiring to maximize efficiency and decrease energy loss. It certainly pays to take time to speak with several installers to weed out any of the less reputable operations. And don’t get hung up on buying the absolute most efficient solar panel out there. A well-designed solar installation, as long as it includes quality components, can have you running off the sun for years to come!

Assessing your electricity use, utility rates, and roof space, your installer will help you decide whether you should install premium Sunpower solar panels or a standard quality panel. Installing solar is a financial decision and standard-quality panels, with their low cost, allow you to recoup your investment as fast as possible. But if you’re just looking for the best components out there, Sunpower has you covered.

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