One of the many great things about solar power is that it's generated entirely at the subatomic level.
That means no moving part—and, hence, none of the wear and tear that's the primary culprit when more conventional technology goes on the fritz.
But, of course, nothing lasts forever.
Though solar panels are immune to the kind of damage that sends most other products to their final destination in some landfill, the amount of solar energy produced still gradually drops over time in a process called "degradation."
Thankfully, solar panels degrade so slowly that the expected lifetime before they need replacement is 25-to-30 years.
But that still raises the question of what happens when their useful lifetime ends.
First, however, let's take a quick look at why solar panels degrade at all.
What causes degradation?
By far the biggest factor is seasonal fluctuations in temperature.
Like everything else in the physical world, solar panels imperceptibly expand when heated and contract when cooled.
When it comes to solar panels, however, this seasonal back-and-forth causes micro-cracks that interfere with the subatomic processes required to generate solar energy.
As these micro-cracks accumulate, the amount of solar energy produced gradually declines.
Fortunately, solar panels degrade at a very slow rate. On average, their power output only declines by a minuscule 1% each year.
That’s why most manufacturers are willing to guarantee that their panels will operate at a minimum of 90% efficiency for the first ten years and 80% by year 25.
Moreover, since electric rates are certain to climb ever higher over the next 25-to-30 years, even solar panels operating at less than 80% efficiency could still wind up providing sufficient value that far down the road.
But, whether it takes three decades or longer, eventually your solar panels will need to be replaced.So, what happens to the old ones?
Can they be recycled? Or are they destined to take up more space in our already too-abundant landfills?
Solar Panel Recycling
The answer to the first question is, yes, solar panels can be recycled. A recycling association based in Europe called "PV Cycle" has developed a 3-part process for recovering over 97% of the materials.
• First, the panels are dissembled into separate components, after which 95% of the glass and 100% of the metal is recycled for use in manufacturing new solar panels.
• Heat is then used to evaporate the plastic that covers the silicon wafers. The evaporated plastic is then used as a heat source when this very process is applied to other panels.
• Finally, the remaining silicon is broken into components, of which 80% is immediately reusable. The remaining 20% is melted together in a process that allows 85% of it to be recovered.
At present, however, there's one pretty big caveat here.
Though a process has been developed for recycling virtually all the raw materials in a solar panel, at this stage of the game there still isn't nearly enough of a demand to make it readily available.
The Law of Supply & Demand
The Solar Energy Industry Association (SEIA) estimates that, by the end of 2021, total US installed solar capacity had reached 121,000 megawatts. Whereas, in 2007, that number was only 470 megawatts.
That means 99.6 percent of the solar panels in use today are less than 15 years old and, hence, still have at least another decade till disposing of them even becomes an issue.
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So, though there are a lot of solar panels sitting on U.S. rooftops generating cost-free, clean and renewable energy, the number that needs replacing each year is still way too small to sustain a robust market for recycling.
And it’s liable to be at least another decade before enough solar panels have reached the end of their useful lifespan to make widespread recycling a reality.
The good news is that means by the time recycling does become an issue, newer and even better methods will have likely been developed.
But the basic fact is that we already know how to recycle solar panels and all that’s missing is the demand.
So, if you’re thinking about going solar today, there are bound to be very good recycling options in the 25 or more years it will take before you even need to start thinking about replacement.