Solar Warranties: The Solar Panels and Inverters
One of the wonders of solar power is its ability to produce clean, reliable energy for over 25 years. There is comfort in knowing that you’ve made a smart decision that will pay for itself and produce clean energy into the next generation. However, how can you feel certain that your investment will produce? The first answer is based on relatively recent history: many solar panels produced in the 1990’s are still producing power. The second answer: warranties.
There are two primary components that most customers think about regarding warranties: the solar panels and the solar inverter. The panels simply sit there and allow electrons to move and create electricity. Their simplicity (no moving parts) allows for long-term warranties based on historical data and rigorous manufacturer testing.
Solar panels have two primary types of warranties. The first is a production warranty. This has evolved over the last couple of years. The primary endpoint of the warranty is a minimum of 80% production at 25 years for most manufacturers. This means that at year 25 the panel’s output is guaranteed to be 80% of its rated output. This is gradually transitioning from a stepped warranty (90% production guarantee at 10 years and 80% at 25 years) to a linear warranty that requires greater production between the steps in the warranty. For example, SunPower’s current production warranty at year 15 is approximately 92% (whereas, in the step-down model, another manufacturer’s would have been 80% at year 15).
The second warranty for solar panels is the product/workmanship warranty. This is more specific to the components. Here is a brief excerpt from Canadian Solar’s description: “… the modules shall be free from defects in materials and workmanship that have an effect on module functionality under normal application… the glass of a module will maintain its integrity … and that the cable and connector plug of a module will remain safe and operational …”. The standard baseline for the product / workmanship warranty has recently increased from 5 to 10 years.
Hail damage is the third coverage under a solar panel’s warranty. For most panels this covers one-inch hail at 50 mph. The “take home”here is that the panels are quite durable. Out of the approximately 150 systems that we’ve installed we’ve only had 3 affected by hail. In each case, the hail was well over baseball-size and insurance covered the required roof replacement and the solar panel replacement.
Now, on to the inverters – a relatively simpler warranty discussion. While, more complex than a solar panel because their electronics convert DC to AC electricity and sync with the grid, inverters still carry a relatively long warranty. For most grid-tied inverters the minimum warranty is 10 years with some as long as 25 years (more common with micro-inverters). Some manufacturers allow the purchase of an extended warranty, from 10 to 20 years, for example.
Ultimately, a manufacturer with a strong track record and a qualified, experienced installer can provide a significant peace of mind as you create clean energy and lower electricity bills for many, many years.
-Dane Glueck, StraightUp Solar President