Solar installations are investments that deliver increasingly greater returns over time as grid electricity prices continue to rise while free energy from the sun remains a constant. However, the lifetime ROI of a new installation largely depends on how long that “lifetime” actually is. Consequently, any homeowner or business owner interested in switching over too solar must understand the actual manufacturing warranties backing whatever systems they explore. These warranties typically cover the 3 main components of a standard PV installation – the panels, inverters, and batteries if you have them.
Most solar panels come with warranties guaranteeing 80% system performance or higher for 20 to 25 years – well beyond the warrantees typically attached to most electrical appliances, cars, and even diesel generators. In addition, many manufacturers also segment their warranties, guaranteeing 90% system performance for the first 10 to 12 years. It’s worth noting that the potential lifetime of a solar PV installation can be as high as 30 to 40 years, with many installations from the 1970s still producing clean energy.
Solar power inverters are responsible for converting the DC current that panels produce to the AC current that most electrical home appliances use. Lower grade inverters typically carry warranties of 2 years, while higher name brands guarantee performance for 10 to 15 years. However, their useful lifetimes can be significantly longer.
Solar batteries store electricity generated during the day for use at night. Most manufacturing warranties last between 5 and 10 years, although their useful lifetimes can be as high as 15 years or more. In addition, many installations don’t even use batteries for on-site storage. By connecting their systems directly to the utility company, users can rely on the entire electricity grid as a de facto energy storage solution.
Protection against faulty workmanship and defective parts usually lasts between 2 to 10 years, depending on the manufacturer and the installer. In addition, many warranties carry stipulations about regular upkeep and maintenance.
If you take care of your system, stick with reputable manufacturers and installers, and take advantage of solar incentives to bring the cost of your system down, it’s possible to earn a healthy return on your investment well before these warranties expire.
Worth noting is if you choose to go solar through a lease or PPA program you are in essence buying a warranty for the period of the agreement. Any maintenance or performance issues falls to the company who the financing vehicle is thru making the warranties meaningless at least for the term of the program. As many leases have a term of 20 years it can be important if equipment warranties extend beyond this period.
Some typical warranties:
Inverter - PV Power Residential PDF
Panels - SunPower PV Module PDF