Understanding the warranty offered by a Solar Installer is imperative when comparing proposal bids. And quite honestly, the fine print and details can get confusing. First, know the difference between a Solar Panel Product Warranty and a Solar Panel Performance Warranty:
1. What is a Solar Panel Product Warranty?
A solar panel’s product warranty covers the integrity of the panel itself, and protects you against failures due to manufacturing defects, environmental issues, premature wear and tear, etc. Most solar panel manufacturers warrant that their panels will not fail for at least the first 10 years, and some extend their warranty periods even longer than that. There is only one company that has a 25 year product warranty. As with most warranties, a longer period is more advantageous to you, if you own your solar system.
Why Does a Solar Panel’s Product Warranty Matter?
If you install a solar PV system for your home or business, by far your most likely scenario is that your panels will perform trouble-free for years. But problems do occur from time to time, so if you happen to experience a problem with a solar panel after it’s been installed, it’s important for you to understand that the rest of your system will not be rendered inoperable… not by a long shot. In all likelihood, depending on the nature of the panel failure, the rest of your system will continue running with the failed panel left in place. But occasionally panels fail in ways that impact the performance of neighboring panels. In either case, it’s the panel’s product warranty that will cover you if you ever need to get a bad panel swapped out for a new one.
Evaluating and comparing the product warranty coverage of panel manufacturers can help assure you that your service and support needs will be covered if a solar panel problem ever occurs. Manufacturers’ product warranties are an important complement to other considerations in assessing not only a panel manufacturer’s technical specifications, but also its business practices. In case a solar panel fails, the manufacturer will ship you a free replacement panel. They will NOT pay for shipping cost and labor cost to replace it. One exception: Sunpower.** This manufacturer has a 25 year product AND labor warranty.
2. What is a Solar Panel Performance Warranty?
The amount of electricity a solar panel produces declines a very small % every year. That’s true of all solar panels, but to varying degrees. A common practice in the solar energy industry is to guarantee that the panels will not lose more than 10%-20% of their power output capacity over the first 25 years. Said another way, panel manufacturers generally guarantee that their panels will produce electricity at 80%-90% of their power output rating at the end of 25 years. Bottom line: A 25 year performance warranty DOES NOT cover a panel failure.
**SunPower is THE ONLY manufacturer of solar panels that offers a 25 year warranty on the efficiency of their panels. The sun power warranty states “the power output will be at least 95% of the minimum peak power resting for the first 5 years, and decline by no more than .4% per year for the following 20 years.” This is 7% more efficient than any other brand after year 10.
Final thought. When comparing bids and warranties of Solar Panels, Ask yourself “what is the probability that the installation company AND the manufacturer will be in business long enough to honor all warrantees in the 24th year of operation?” A related article: “Fallen Solar Companies”