How Long Do Residential Solar Panels Last?

These are questions every smart consumer should ask before installing solar panels:

  • What is the lifespan of solar panels?
  • What about solar panel efficiency over time?
  • Will I need to install replacement solar panels at some point?

If you’re considering saving money on your electricity bills by going solar – and especially if you’ve already had modern solar panels installed! – here is what you need to know.

What Are Solar Panels Made of?

When considering making the switch to solar, wondering how long home solar panels last is a question that may come up. Knowing the inner workings of solar panels will help you understand more about their expected solar panel lifespan.

Scientifically speaking, solar panels are known as “photovoltaic panels,” made of a thin film of silicon with a mix of chemicals (usually silicon, boron and phosphorus) that convert sunlight into electricity. The panels’ metal casing and wiring capture this energy for use in your home. Naturally, there are many different configurations of panels in use today.

What is a solar panel made of?

At Sunnova, we exclusively use “Tier 1 and Bankable” equipment which is the highest classification for residential solar panels and has been heavily vetted by the major banks.

Tier 2 Solar panels

Small to medium-scale manufacturers
  • No or little investment into research and development
  • User only partial robotics, also reliant on manual work from human production lines
  • Usually producing panels for 2 to 5 years

  • .

Tier 3 Solar Panels

Assemblers only - 90% of new solar PV
  • No investment in research and development
  • Assembly panels only - does not manufacture silicon cells
  • Uses human manufacturer lines for human soldering of solar cells instead of advanced robotics
  • Assembling panels for 1 to 2 years

How Long Do Solar Panels Last?

As with all things, solar panels will lose some efficiency over time, but fortunately, the degradation is minor. The maximum possible output of solar panels only reduces by approximately 0.30% per year. At that rate, solar panels are capable of producing up to 93.04% of their original output even after 25 years!

Note that Tier 2 and Tier 3 solar panels, the kind we do NOT use at Sunnova, degrade at a much faster rate, reducing their efficiency over time by 11.33% and 17.53% respectively over the same 25 years!

Degradation Rate

0.30%

Reduction Over 25 Years

6.69%

Amount of Orginal Out After 25 Years

93.04%

Degradation Rate

0.50% ↓

Reduction Over 25 Years

11.33% ↓

Amount of Orginal Out After 25 Years

88.67% ↓

Degradation Rate

0.80% ↓

Reduction Over 25 Years

17.53% ↓

Amount of Orginal Out After 25 Years

82.47% ↓

These statistics come from a study by the National Renewable Energy Laboratory (NREL). NREL is a national laboratory operated by the U.S. Department of Energy (DOE).

According to the NREL, photovoltaics “took off” in conjunction with the Space Race of the 1950s and grew through the efforts of the DOE. The NREL report also shows a steady improvement in solar panel performance over the years.

The report states,

As module durability increased during the last three decades, module warranties increased accordingly.

— NREL

Solar Panel Monitoring and Service Plans

While the solar panels are highly durable and built to last at least 25 years, many components are required for a home solar system to operate. Panel racking, solar inverters, and solar meters require professional attention if they are not functioning as they should. If you purchase a Sunnova home solar service or Sunnova SunSafe™ solar + battery storage service, your service comes with a 25-year Sunnova Protect™ Platinum plan which safeguards all these components with worry-free, hassle-free maintenance, monitoring, repairs, and replacements.

And, even if you already own a home solar system you purchased elsewhere and need coverage, we can help ensure your home solar system performs to its maximum potential when you sign up for one of our Sunnova Protect™ Services plans.

Home Solar Panel Warranty  

Your time is valuable! With our home solar protection plans, if your home solar system has an issue, our solar experts will detect it through our monitoring system, manage repairs for covered parts from start to finish, including negotiating with manufacturers, handling your claim, scheduling, and managing the repair or replacement. There’s no hassle or guessing what to do - our solar experts will take care of it. Learn more at Sunnova Protect™ Services.

Without Sunnova Protect™, you may end up spending a lot of money over the next 25 years for the many potential issues that could arise with your solar panels and other system components.,

Listed below are repairs that could potentially be required at some point to keep your panels performing at their best.

Solar Inverter Issues

The solar inverter is the tool that converts DC electricity into AC electricity for your home to use. You can expect to replace your inverter every 10-15 years. A top- of- the- line and well-maintained inverter could last up to 20 years with a slight drop-in efficiency.

  • The two most common types of inverters are string inverters and micro-inverters. String inverters connect a group of solar panels to one inverter. Micro-inverters are an integrated part of each individual panel.

  • In both cases, you may first notice an inverter issue if you begin to lose some of your expected solar energy production. If you have a string inverter setup, you may also notice an error message on your inverter. However, if you have micro-inverters, please DO NOT get up on your roof to check your micro-inverters!

If you’re a Sunnova customer, the inverter is covered by Sunnova for 25 years. Compare this to the typical manufacturer inverter warranty, which covers the inverter for only 5-12 years. We also monitor your solar energy production 24/7, and we’ll alert you to any issues.

Wiring Damage

Wiring may become loose over time due to heavy winds or other weather events. While it’s rare, you’ll need to have your solar installer check on it if you suspect wire damage. We never recommend you get on your roof to check your solar panels.

Also, water damage may occur if water is able to enter wiring conduits. In the case of wiring issues caused by water damage, you’ll not only need a trained solar repair expert but also an electrician to check out the area before any work can be done.

Circuit Breaker Trips

If your solar system is causing your circuit breaker to trip, you could be facing a number of different issues caused by the elements, system connections or a faulty breaker panel. Also, if your solar panel conductors are damaged, improperly installed or not up to code, they can cause your circuit breaker to trip.

Again, this will require a professional to repair.

Racking Replacement

The racking system for your solar panels is drilled directly into the roof, so it is very exposed to the elements, potentially leading to slow deterioration, depending on what part of the country you live in.

Solar Battery Replacement

If you opted to have home solar battery storage added to your system, its performance may begin to degrade at about the 10-year mark. With Sunnova SunSafe® home solar + battery storage service, you can have confidence knowing your home solar system and home solar battery are covered by Sunnova Protect™ for 25 years featuring worry and hassle-free maintenance, monitoring, repairs, and replacements.

Learn more about home solar battery storage.

Keep in mind, Sunnova customers with our 25-year Sunnova Protect™ Platinum plan will not need to pay out of pocket for home solar system repairs.

Solar panels may continue to perform satisfactorily for many years beyond their 25-year warranties, provided they are not they aren’t damaged by wind, debris, or other external factors. Fortunately, the risk of external damage is low because the panels are durable and don’t have any moving parts.

Cleanliness of solar panels is only briefly mentioned in the NREL study, but common-sense dictates that the more unobscured sunlight a panel receives, the better its performance.

Of course, despite the efficiency and resilience of the solar panels, production may be lower in the event they are shaded by trees that are not trimmed regularly, structures or other structures or the accumulation of dust and debris may block the sun. from reaching your solar panels and potentially reduce their solar energy output beyond the expected degradation for whichever type of panel you have.

How to Clean Solar Panels: Easy Recommendations:

  • Spray your solar panels with a garden hose, safely from the ground – do not get on your roof.
  • Do not use harsh cleaning chemicals that could damage the solar panels
  • You should not clean your solar panels during the hottest part of the day because the extreme temperature difference between the water and the solar panels may cause the glass to crack
  • Clear away debris such as tree branches blown about by windstorms
  • Snow will naturally melt and slide off.

In conclusion, if you did not get your home solar system through Sunnova, it may pay to fully understand your current warranty and monitoring service. If you are not able to monitor your solar system or only have manufacturer’s warranties, it may be time to consider an upgrade if you deem it insufficient. Expecting a minimum of 25 years’ worth of optimal performance from your solar panels is the new norm upon which all other considerations should be based. Remember, Sunnova Protect™ comes with all Sunnova home solar and solar + battery storage systems.

And, if you already have a home solar system, even if it was not installed by Sunnova, you can easily add one of our Sunnova Protect™ Services to help ensure your system performs to its maximum potential!

Learn more about service, monitoring and protection plans from Sunnova