Solar panels buying guide - Energy saving - CHOICE

Best Company for solar Panels

Solar Panels / June 3, 2016

You’ve heard of SunPower, LG, SolarWorld, Q-Cell, and maybe even Canadian Solar, but which one is the right fit for your home? To figure that out we are going to review cost, degradation, warranty, efficiency, technology, and value.

The first consideration most homeowners will review is the price of the panel. Therefore a good starting place is to remember that at the end of the day solar panels are all producing one thing, electricity. A 5 kilowatt (kW) SunPower system, a 5 kW LG system, and a 5 kW Canadian Solar all produce the same amount of energy. That means that if you utilize the same roof area for all three of these systems, you can expect nearly identical energy outputs – at least for the first year.

Sunpower clearly takes the cake when it comes to the efficiency of the solar panel, and the hardware warranty that comes from the company. However, when it comes to realizing the most valuable solar panel, Sunpower only reigns supreme when a project requires the most efficient use of the available roof space. If you have the available roof space for a less efficient panel, you will save thousands of dollars by going with a lower cost solar panel for your house. As a consumer, it makes you question the variance in price. If your system is producing the same output, then is there value in paying 20-40% more for certain brands?

SunPower does have a clear edge in certain aspects. They have the highest efficiency panels available in the market right now. Efficiency is the ratio of the production output to the surface area of the panel itself. The highest SunPower panel efficiency is 22.2% and its output is 360W. For comparison, Panasonic's highest solar panel is 19.7% efficient with an output of 330W, and the LG panel has 19.5% efficiency with an output of 320W. If you want the most juice for your system’s footprint, SunPower may be the way to go.

Just like everything else, your solar panels will age, and as they age their production efficiency will drop. This is called degradation. Degradation happens for a variety of factors including extreme temperatures, intense UV rays, and soiling. PV manufacturers perform advanced degradation tests on their panels to ensure they are not degrading at a faster rate than they are expected to. Depending on the panel the annual rate of maximum degradation is different. Some yearly degradation rates include:

The most important thing to consider with degradation is that these annual rates set by solar manufacturers are a maximum rate of degradation allowed per year. If the solar panel degrades at a faster rate than the one set, they will replace the defective panel. Your monitoring system will pickup which panel is producing less - this is an indicator that the panel is degrading faster than the maximum rate allowed. Even with normal degradation, your panels are still expected to perform up to 25 years and beyond. When you look at the numbers it is important to consider if a 0.2% yearly degradation difference is worth a 30% increase in cost.

Product warranties are important to look at as well. The product warranty covers defective materials in the manufacturing of the panel. SunPower is the leader here. They have the strongest product warranty in the industry at 25 years. If your SunPower panel stops working within 25 years, SunPower will replace it – labor included. The next closest competitor, Panasonic, is 15 years. LG has a 12-year product warranty. Most other brands have a 10-year warranty.

When might a SunPower system be the right choice for you? Because of their high-efficiency panels, if you have limited roof space and your chief concern is getting the highest producing kWh system, SunPower may be the way to go. There are other high-efficiency panel brands (ex. LG and Panasonic) available that are 1-2 percentage points lower in efficiency but 20-30% lower in cost. These panels can be great options for consumers who are limited in roof space and more motivated by cost.

SunPower is also the clear cut winner on warranties with its 25-year product warranty. However, panel failure rates have become so low that it is highly unlikely that you will have any issues within that 25-year period. In the off chance that there is an issue, it would likely be only one panel.

Ultimately, which panel you should get depends on your goals and desires for your solar system. SunPower will be the right fit if you are looking for:

  • Highest Efficiency
  • Lowest Degradation (Annual Rate)
  • Longest Hardware Warranty

If you’re looking for the most bang for your buck, SunPower is likely not the best choice. Solar panels produce one thing, electricity. So, when you consider a system that produces similar kWh production, it makes you question SunPower’s value. When it comes to solar panels, more expensive does not mean better value.

Still up in the air about which solar panel is right for you? Please call (888) 454-9979 or click the button below and one of our experts will be in touch to help answer any questions you may have!