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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.
Carter called for solar panels to be installed on the White House in 1979. Modern ones are probably way more efficient but they were definitely a thing.
Solar panels have also been used in space mission for a very long time. The first solar powered probe was Vanguard 1 in 1958