@polychrome My favorite example of this kind of thing is the flush toilet. I remember when I was a kid the power went out and I was surprised when my parents told me the toilet would still flush. If someone were to invent the toilet today it'd definitely require electricity
Another one is the mechanism that makes the gas pump shut off when your tank is full, which is also non-electric - only because it became necessary before reliable sensors for that kind of thing were invented
Sunbeam City is a anticapitalist, antifascist solarpunk instance that is run collectively.