What degrades in solar cells ?

[Externet]

Hi. 

Recycling of solar panels will be addressed soon, if not already a thing to consider.  What happens to the cell that loses some efficiency in a couple of decades ?   How much is the efficiency loss ?  ~20% ?    What could it be in 100 years ?   In my young years studying electronics, read  "a transistor is theoretically eternal"  The silicon in them is not exposed to sun rays but encapsulated in epoxy.  Is that what makes a conservation difference ?

What is the 'aging agent' ?  Solar radiation ?  temperature cycles ?  moisture ?  particles ?

There is mainly two types, the monocrystalline and the polycrystalline cells.  Always read about their efficiencies but never saw longevity differences published.  Is this a physics more than a chemistry thing ?  ---> Please move as deserved.

There is a smell that large solar plants sell their aged panels at a good 'discount' and profit from it instead of paying for recycling...  financial strategies...

[npts2020]

 

Weather, especially moisture and temperature changes;

"Much of the weather-related deterioration of solar panels is due to rapid swings between hot and cold, freezes during periods of high humidity, hot and humid weather and UV radiation. Rapid changes in weather can cause materials to expand and contract, weakening connections like the soldering inside the panels. During freezing temperatures with high humidity, expanding ice can create separation between materials. UV radiation can cause discoloration of surfaces, which can limit the amount of light that reaches the solar cells. Discoloration was one of the most common problems in one study by the National Renewable Energy Laboratory (though that information [PDF] is over 10 years old at this point)."

from; https://www.cnet.com/home/energy-and-utilities/yes-solar-panels-deteriorate-over-time-heres-what-you-need-to-know/

 

Weather deteriorates solar panels more than any other factor and is usually calculated at .5% efficiency loss/year so that after 20 years panels will still produce at 90% of whatever peak performance was to start. This is "worst case" outlook so actual efficiency loss may be as little as .1% or less annually. Germany seems to have some still producing electricity, even after 40+ years of operation.