Re: move mining to the mountains
It's not the loading that equates to the energy it's the geography of a volcano or tectonic plate activity that raised the rocks up in the air.
It's the same as a waterwheel not being perpetual motion, it is the energy from the sun that drops rain higher up then the sea that the water flows down to.
However a waterwheel was a remarkable clean energy device. A truck that needs no electricity to recharge is also a pretty impressive idea. It doesn't need to be 'magic'.