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Solar modules deployed in France in 1992 still provide 75.9% of original output power
(www.pv-magazine.com)
This is a most excellent place for technology news and articles.
They already are, at least for the smaller ones. You can go to your citie's parks and recreation department to get some. All those solar panels that power various signs and lights have been collected and replaced for years. I picked up a few years ago in Lexington, KY, for next to nothing, and they worked just fine for the lights that I wanted to power, despite only outputting less than 50% of their original power.
Not sure where you would find the full size ones like these pictured.