Just so. Though some were adapted to steam turbines to generate electricity for farm lighting and Agric-Alert radio net equipment.
I saw one once (a black painted barrel) suspended over an outside shower. I still plan to make one of them.
Such worked reasonably well in places where the African snow shone down on them. In my Wyoming location, they're somewhat less effective when covered by three feet or more of snow.
btt
What a beautiful animal that is.
I tell people my nom de plume “wiz” is an Indian (Native) name. It means “sound on prairie, made by buffalo”.