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Solar power and storage prices have dropped almost 90%
(interestingengineering.com)
This is a most excellent place for technology news and articles.
They are not rare. It is the fastest growing energy production mode and is growing faster every year.
Residential installations lag behind the commercial due to installation costs, but they are blowing up as well. I can walk around my neighborhood and see a couple dozen homes with it.
It's also highly regional. The further south in the northern hemisphere the more common.