Solar panels go up on your roof and produce energy like shiny silicon champions. But up there, they’re exposed to harsh conditions like hot, sunny days, cold winter nights, rain, wind, and hail. How long can they possibly last out in the elements?
Quite a while actually.
The panels in the picture below are installed on the front of the Betty Bear Hut, a recreational haven in the central Colorado backcountry; a place that sees harsh winters, blistering summers, and a whole lot of bright sun at 11,100-feet elevation.
They’ve been there since the mid 1990s, and they still produce nearly as much electricity as they did when new.
That little strip of four panels is just one of many old solar installations that are still rocking decades into their service, and it shouldn’t come as a surprise that decades of service are the rule, not the exception, for solar panels.
One of the misconceptions about solar is that it’s an untested technology. Skeptics argue there’s no way to tell how long the panels will last, or that they will require costly maintenance on a regular basis.
We’ve done the legwork and determined that there really isn’t any data to indicate solar panels won’t be the rigorous long-lasting electricity-generating beasts you hoped they would when you first bought them. In fact, evidence from around the world shows that solar panels last for decades and keep producing reliable energy with little degradation.
In fact, solar panels have been used over 60 years to keep communications and exploration satellites running, and the astronauts on the International Space Station have trusted their lives to solar power for over 13 years. IN THE HARSH ENVIRONMENT OF SPACE.
But anecdotes tell incomplete stories. We looked at some of the data that’s out there, and the findings are very promising. For one, even the first solar cells, developed 60 years ago, are still working today!.
The most complete review of studies of solar panel efficiency over lifespan, published by the National Renewable Energy Laboratory (NREL) in 2012, looked at degradation rates in nearly 2,000 solar installations. Degradation is basically the gradual decrease in efficiency of a solar panel over time, and it’s something of a bogeyman among solar naysayers, who say that solar panel degradation means lower-than-expected earnings over the life of the panel.
Regardless of what solar power’s detractors say, nearly all solar panel manufacturers guarantee that the panels they make will maintain above 80% efficiency by the end of a 25-year warranty. But those warranties are based on conservative estimates. The NREL study found that, for traditional silicon-based solar panels, the median reduction in efficiency is about 0.5% per year, which means that the panels operate at 88% efficiency, even after 25 years.
Solar warranties are a pretty safe bet. Many solar panel manufacturers have been in business for decades, and even when they haven’t, they’re increasingly turning to insurance-backed warranties that guarantee coverage even if they company becomes insolvent in the future.
What about expensive equipment replacement and maintenance?
Solar panels are not expensive to maintain. Most manufacturers recommend that the panels get sprayed off once a year, but rain usually does a fine job of washing panels off without any intervention from system owners. Other regular maintenance is usually not necessary.
As for replacing parts, there are a few components in a solar system that could need replacement. If a panel fails outside of the manufacturer’s warranty, it costs between $150 and $200 to replace. If your system uses a centrally-located inverter to change the DC power produced by the panels into AC power that can be used by the electric grid, it might need to be replaced in 10 or 15 years at a cost of about $2,000, but many inverter manufacturers offer 10- to 12-year warranties; some even extend those warranties to 25 years. And micro inverters, the kind that attach to each individual solar panel, cost much less to replace and are usually warranted for 25 years.
With all the data on panel reliability and all those great manufacturer performance guarantees, you can rest assured that your system will keep producing reliable power, with little needed maintenance, long after your system has paid for itself. Heck, in 25 years, you might be the person scrambling up on your roof to show how your panel is just as efficient today as it was when it was first installed.
Last modified: January 22, 2019