“Renewables” aren’t really reusing energy so much as the source of the energy can or will be replenished rather than running out on human timescales.

For instance, we can burn oil and we can burn trees. There is currently a finite amount of oil on the Earth and a finite number of trees.

But we can grow more trees. We can’t make more oil. So trees are renewable. Oil is not.

The overwhelming majority of “renewable” energy sources that will not run out are actually just capturing energy put out by the sun.

If we want to be very technical, that energy is also finite and will run out, but the sun will expand and destroy the Earth long before that happens, so worrying about running out of that source of energy doesn’t seem particularly worthwhile.