How Long Do Solar Panels Last? Degradation Explained

How long do solar panels last?

The short answer is 25 to 35 years for the panels, according to the federal Department of Energy. Many people think panels switch off at year 25. They don't. A panel at year 26 still makes power, just a bit less than it did new.

The parts around the panels often need help sooner. Inverters (the boxes that turn panel power into home power) usually wear out before the panels do. Microinverters, like Enphase units, tend to last longer than one big string inverter. Over the life of a system, plan on the panels going the distance and an inverter swap along the way.

What is solar panel degradation and how fast is it?

Degradation is the slow, natural drop in how much power a panel makes as it ages. Sun, heat and normal weather wear on the cells over time. It is slow and steady, not a sudden fall.

The most-cited data comes from the National Renewable Energy Laboratory (NREL). Its review of published field data found a median loss of 0.5% a year (Jordan and Kurtz). Here is what that rate means over time, as simple math:

If your system loses power much faster than this, something is wrong. It is worth a check rather than shrugging it off.

What a panel warranty covers

Most panel makers give a performance warranty. It promises the panel will still make a set share of its first output after a set number of years. The exact terms differ by brand, so check your own paperwork. If output falls below that promise, Service Solar Pros can test the system and help you file the warranty claim.

Does Florida's climate make panels degrade faster?

A little, yes. The Department of Energy notes that high heat can damage cells and shorten panel life. Central Florida's strong sun, hot roofs and damp air all add mild stress compared to a cool, dry place.

The key word is mild. Heat nudges the rate up a bit, but it doesn't wear panels out in ten years. The bigger Florida issue is dirt that cuts output without hurting the panel at all. Pollen film, hard-water spots and bird droppings can quietly cost you power.

That loss looks just like aging on your bill, but a cleaning reverses it. We cover it in do dirty solar panels lose efficiency.

How do you know if your panels are degrading normally?

Watch the trend, not one reading. Compare this year's output to past years for the same season. Use your monitoring app or your FPL or Duke Energy bills. A slow, steady drop of about half a percent a year is normal aging.

What's not normal:

• A sudden step down in output. That points to a failed panel, optimizer or inverter, not aging.
• A fast slide, losing much more each year than the table above shows.
• One string or section making far less than the rest.

These usually mean a fault or dirt, and both can be fixed. The trouble is that slow losses hide well. Owners often blame "old panels" for a real, fixable problem and lose money for years.

If your numbers slide faster than the table, a diagnostic and repair check can tell aging from a fault. Our guide on why panels stop producing covers the common causes.

How can you make solar panels last longer?

You can't stop aging, but you can protect the output you paid for. What helps most in Central Florida:

• Keep them clean. Regular professional cleaning removes pollen, dust and hard-water film. Over time, that film can etch the glass.
• Keep critters out. Birds and squirrels nesting under the panels chew wiring and foul the glass. A critter guard made of mesh stops that damage, with no drilling into the roof.
• Catch faults early. A shaded, cracked or hot-spotting panel drags down the panels around it. Fixing it protects the whole string.
• Service the inverter and wiring so the rest of the system keeps pace with the panels.

The simplest way to cover all of it is a maintenance plan. It brings scheduled cleaning and checkups that keep output high and catch small problems early. Plan members also get lower travel and hourly rates.

Service Solar Pros works on every brand and any original installer, from Enphase to SolarEdge. We serve The Villages, Leesburg, Ocala and all of Central Florida.

👉 Book a system health check or call (407) 270-2542.

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