SunPower solar panels review

SunPower Solar Panels: The Complete Review

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SunPower solar panels are one of the most frequently requested solar panel brands on the EnergySage Solar Marketplace, and for good reason. SunPower panels are often the most efficient (read: powerful!) products on the market today, and they offer an industry-leading warranty. For many years, SunPower has been a fully-integrated solar shop: manufacturing solar cells & panels, and then offering sales and installation services for residential and commercial applications as well. Recently, SunPower announced that they’re spinning off their manufacturing arm into a new company–Maxeon–to focus on installing solar panels.

How SunPower X-Series, E-Series, and A-Series solar panels compare to other panel manufacturers

As you evaluate overall solar panel quality, there are four key metrics that you should consider: efficiency, performance, warranties, and price. To help you with your decision, EnergySage has developed SunPower reviews for each metric, along with a comparison of SunPower solar panels (including the esteemed SunPower X-Series) against the other leading panel manufacturers offered on the EnergySage Marketplace.


The term “solar panel efficiency” refers to how well a solar panel can convert sunshine into useful electricity. Given the same conditions, a high-efficiency solar panel can produce more electricity than a lower-efficiency panel of the same size. For this reason, a higher efficiency rating is generally preferable.

SunPower solar panels are the most efficient panels currently available on the market in the United States. While the majority of solar panels fall in the 14% to 18% efficiency range, SunPower’s products are much more efficient – between 19.6% and 22.8%. If efficiency is your top priority, the technical specifications of SunPower solar panels are unparalleled.

Performance (temperature coefficient): SunPower X-Series

For this portion of EnergySage’s SunPower reviews, we use the temperature coefficient as an indicator of panel performance. The temperature coefficient represents how well your solar panel can handle less-than-ideal conditions. Solar panels, like other electronics, perform their best when they are kept cool (ideally around 25° C/77° F). You can use the temperature coefficient to get a sense of how your panel’s performance will change during hot sunny summer days.

For every degree above 25° C (77° F), your solar panel’s electricity production will decrease by its temperature coefficient. For example, SunPower’s SPR-X21-345 panel has a temperature coefficient of -0.3%/°C. This means that, if the panel’s temperature increases by one degree from 25° C (77° F) to 26° C (79° F), its electricity production will be reduced by -0.3%. If its temperature increases all the way to 35° C (95° F), electricity production will decrease by 3%.

Ideally, you want the lowest temperature coefficient possible. SunPower’s solar panels offer some of the best temperature coefficient ratings on the market today, between -0.35 and -0.29.


Whether you’re buying a TV, a car, or solar panels, the manufacturer should stand behind their product with a strong warranty. A solar panel’s materials warranty (sometimes referred to as the product or equipment warranty) guarantees that it will be replaced in the event of equipment failure due to manufacturing defects or environmental issues.

Most solar panel manufacturers offer a 10-year materials warranty, but the best solar panels come with a 12, 15, or even 25-year warranty. In keeping with SunPower’s industry-leading position in the other metrics we’ve assessed, the company offers a 25-year warranty against any defects in their products.

Every solar panel’s production naturally degrades over time. The performance warranty is a manufacturer’s guarantee that your solar panels’ production won’t degrade too quickly. In addition to a leading materials warranty, SunPower offers one of the best performance warranties of any solar panel manufacturer we’ve reviewed. Most solar panel brands offer a performance warranty stating that their panels will still be producing at somewhere between 80% and 83% of their original capacity after 25 years. By comparison, SunPower’s performance warranty is 94% after 25 years – a full 9% to 12% higher than most other panel manufacturers offer.

How much do SunPower solar panels cost?

Our SunPower reviews wouldn’t be complete without a discussion of how much SunPower solar panels cost. As you might expect, if you want to invest in the highest-quality solar panels available, you’ll end up paying a higher sticker price as a result.

However, the price of SunPower solar panels might not be as high as you think. We reviewed quotes offered on the EnergySage Solar Marketplace that included SunPower solar panels and found that these systems were priced between $3.14/Watt and $3.56/Watt. By comparison, the average price on the Marketplace during the same time period was $2.76/W – SunPower systems were pricier, but not by an astronomical amount.

This means that, for a 6 kW system, your gross cost would be anywhere from $18,840 to $21,360. However, remember that most homeowners end up paying much less than the total gross cost. There are plenty of solar incentives and rebates to help you reduce upfront costs, including the 26 percent federal tax credit for solar.

How to find the best price on SunPower solar panels 

SunPower panels are, without a doubt, some of the best solar panels available today. When EnergySage ranked the best solar panels on the market, our SunPower reviews were the highest of any panel brand.

If you have a limited amount of space and need to maximize your solar panel system’s production, you can’t go wrong with an installation that includes SunPower solar panels. However, not every homeowner needs the most efficient panels available on the market. If you have enough space for a larger system, installing slightly less efficient panels may give you the performance you need at a slightly better price.

The best way to determine whether SunPower solar panels are the best solar panels for your home is to review multiple quotes with different solar equipment options before making a decision. When you compare all of your options on the EnergySage Solar Marketplace, you’ll find the right combination of price and quality that meets your needs. When registering, simply note in your profile that you’re interested in receiving quotes that include SunPower solar panels for your home. Many of our qualified, pre-vetted solar installers are part of SunPower’s certified solar installer network, which means you can be confident that every aspect of your solar system installation meets the highest standards.

60 thoughts on “SunPower Solar Panels: The Complete Review

  1. Joe OBrien

    Although Sunpower has been fine the company that represents them Eclipse Energy has not. On September 2019 during the sale of solar panels and install by Sunpower through eclipse energy, managing partners Joe Salonia and Adam Zucker stated that upon completion of the project they would write a check to me for $2400 to compensate for a increased install cost that they originally did not quote for that Sunpower charged. This agreement was made both orally and through email documenting the agreement. The completion date of the install was in March of 2020. After several attempts to reach Joe Salonia both by phone and email I finally received a response on June 11, 2020 in which Salonia again stated he remember the agreement and would have a check sent out. Since June I have sent several emails and have received no reply from Salonia or anyone else from the company. It is clear to me that Salonia and Eclipse Energy is breaching the agreement we have. Because Eclipse Energy is the area installer/dealer I do not recomend sunpower if used with Eclipse Energy.

  2. C Murphy

    My panels haven’t worked in two years. And I lease them I just recently found out every single inverter is bad and I have 42 panels. Because I lease them I was told sun power would monitor my system. I also monitor it. When I told them there was something wrong two years ago they blew me off. Now my system has barely produced 4kwh this whole year and I’m out thousands and thousands of dollars in electric bills and a fraudulent Sun Power Contract. Or should I say Sun Power Broke our Contract. They told me I have to wait another whole month before I can get someone out here. And then when it’s fixed They will see how much the system produces and then reimburse me for what they decide. I think not. You broke the contract. If I broke the contract with you. You’d put a lean on my house and destroy my credit.

    1. Jay Naidoo

      Hello C. Murphy, I’m sorry to hear that you’re experiencing servicing and equipment issues related to your leased SunPower equipment. Please know that any underperformance resulting from equipment failures are addressed through the Production Guarantee referenced within your lease agreement.

      We would appreciate an opportunity to investigate your specific situation in detail to determine whether there’s anything our Executive Service team can do to further assist. Please send me a message with your contact or case information at your earliest convenience.

  3. Doug Demers

    There is a lot to be said here. There is no argument that SunPower has some of the best products available. There was no issue with the panels themselves and the installation by SkyLine Solar was excellent.
    Customer Service, communication, and coordination leave a lot to be desired and is widely known by their competitors and is the first thing competitive sales agents mention. Even the 3rd party agents for SunPower sheepishly admit that it is not the best.
    My project took much longer than necessary to get to the installation point. There are unavoidable delays in projects of this nature but delays from lack of planning and oversight are not acceptable. There was issue after issue with permitting and equipment ordering that could have easily been mitigated by minimal effort and planning. One glaring instance was getting a voicemail at 8:30 on a Friday night telling me my scheduled install for Monday was delayed because the equipment was not in.
    The biggest frustration was a post installation issue with the monitoring app and it was eventually discovered that there was a configuration issue with my equipment. There was no wiring problem and the meters were reading correctly but the energy usage was not being reported correctly using the SunPower monitoring software. The immediate problem was corrected and 1 weeks’ worth of historical data fixed, but the rest of the data was left incorrect. This is where the lack of customer support got to the point where it was actually sad. Week after week, phone call after phone call and no update or resolution. Promises of the case worker calling back in 24-48 hours and never hearing a thing. It’s still ongoing after close to 2 months. The last customer service agent I spoke indicated this should be resolved in 5 days.
    Part of the sales pitch was a rebate from SunPower after project completion. I received notification as soon as the project was done and paid for that I would receive my rebate in 3-7 weeks which aligned with what had been communicated by the 3rd party agents. I called after it had been 8 weeks only to find out that they were now saying 10-12 weeks and were waiting for “Funds to be released”. Really? Again, no sense of commitment or proactive communication and an entirely different arm of SunPower business.
    My opinion is that the poor project management and lack of customer support show a lack of commitment to excellence for customer communication and support. The problem is not in isolated pockets but is systemic throughout the organization.

  4. scott halley

    Sunpower Worst solar company to get things fixed. Sunpower Customer service is located in the Philippines Just and FYI. Not even had solar 6 months too and having big issues. Enjoy the read. Here is the Issue. On August 13th there was a power outage for 1 hour and Sunpower solar production is not going to SCE grid now since this happened. I call sunpower solar daily to have a tech come to do an actual Physically check on their equipment but they always say they will get a call back. That never happens. I have had SCE come out and Physically check their equipment panel. We also did a circuit breaker reset and still nothing going to SCE. Southern California Edison are stating it is the solar system(sunpower Corporation) and it must have something wrong with the actual components from sun power. Online it shows sunpower production. However it is showing it as far less than it used to on average which also is a sign of something wrong. SCE. Edison is not getting anything and that is the main issue. Actual component issue is with sun power not the local utility company. My bill has also jumped to almost last year’s summer bill cost when we didn’t even have solar. Need someone from Sun Power to come out to my property at 8364 telegraph rd, Downey ca 90638 and fix or replace what every blew out on there system that is still covered by the warranty. Keep getting the run around and promises that i would get call backs. Go figure no call backs ever and i call them daily to try and get a tech out to fix this issue. Maybe this review might help. Avoid sunpower if you can worst customer service i have ever had.

      1. Georgia

        I call and talk to a supervisor. I have one specifically I am working with. My last call to get something done was over 3 hours. I cannot say my issue is resolved but I got to skip the step of a meaningless sight visit before the “next step” fix. The problem is there is no real leverage you have. They have your money…they have the excuse that they have “processes” to follow evading common sense at all costs. You have to fight and say that what they propose as a solution is “unacceptable”. DO NOT just talk to the first service rep. Get you a good Supervisor and don’t get off the phone until you get what you need. Like I said though, I spent over 3 hours just today trying to get to that step…

    1. Jay Naidoo

      Hello Scott, this is Jay from SunPower. We initially discussed your concerns on September 10 and recently completed a site visit which confirmed that the system is operating as designed. You also mentioned that the issue appears to have resolved itself and no further action is required. It is unfortunate that this occurred but please know that we value your business and are happy to address any future concerns you may have.

      – Jay N.

  5. Angie

    I also had a SunPower system put in this summer. During the presentation, I was informed that each panel had its on invertor, and that performance can be monitored. One of the main reasons for purchasing the SunPower system is that they had the best efficiency ratings on their panels.

    I was also told during the sales pitch that you could monitor each panel to make sure that everything was working. I have since come to find out that is NOT the case. The only information that you can get is that of the whole system. Based on this, I wouldn’t have any knowledge if the performance meets the warranty that they offered.

    I would not recommend SunPower panels unless they could offer individual tracking.


    1. Jay Naidoo

      Hello Angie,

      SunPower has the ability to view inverter level detail to assist with troubleshooting and remote diagnosis. While this level of monitoring is not offered to end customers, we do offer cumulative production data through the SunPower monitoring website ( or smart phone application (IOS and Android). From there, you can customize and export the cumulative energy production data to suit your needs. In addition to production monitoring, the site will also display error messages reported by the equipment. Please contact our customer service team at 1-800-786-7693 if you have any questions regarding the monitoring site or if you discover any issues with your system performance.

      -Jay N.

      1. Shaun

        Hello Jay,

        Panel level monitoring is a standard in the industry. You have it internally and it needs to be made available to your customers. This is how end customers can tell whether individual panels are having issues with production. It lets us know which panels need to be replaced because they aren’t performing properly and it tells us where shading is causing issues with our output so we can deal with the source of the shading. We are being asked to pay a huge premium for your panels and we expect to have at least the standard for the industry in reporting.

    2. Georgia

      Same here. They sold me the PVC in the end with the one inverter…which is failing and they refuse to replace. Jumping thru hoops here. Much better options out there…move to the next reliable company folks!

  6. Ziddo

    I installed 12 Sunpower 400W panels in October 2019 and as of June 2020, three panels already have bad microinverters that need to be replaced. I called Sunpower and they have referred my case to their product engineers. My daily production has dropped from about 30KWh to just about 20KWh. Also their monitoring system doesn’t let you monitor the production of each panel and so you have to figure out if your system is not producing enough. I have chatted with Sunpower people and there is no plans to have per panel monitoring for customer. Now I am wishing I had gone with LG that had a 5.1 KW system instead of the 4.8 KW from Sunpower for about the same price. I would advice potential solar clients to get at least three quotes and then compare the pros and cons of each system.

  7. Joel

    I have had one of the worst customer experiences I have ever had dealing with Sunpower Solar to transfer the lease for the sale of my home.

    I had to call several times and spend hours on hold to get the lease transfer documents in the first place (I was repeatedly lied to and told I would receive the docs by X date, then nothing would happen and I would have to call again). Finally, once we signed and sent everything in, Sunpower promised to get the documents in today so we could close on time. Now Sunpower missed yet another deadline with no contact or any information whatsoever.

    I paid $300 for this solar lease transfer and want a refund, and if the home sale runs into any issues, I am going to hold Sunpower legally responsible for my losses.


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