Some boomer said these things are powered by gravity?

No.12474883 ViewReplyOriginalReport
How can these things be powered by gravity and if they can why doesn't the oil industry just hook them up to generators, why even pump oil with them at all at that point.

Pretty sure it was just a boomer misconception but he seemed pretty sure the old ones in the middle of nowhere needed no power source to operate only a crank to start it.