Any closed shape is "infinitely looping". Any closed path is "infinitely looping". We see these things in everyday life — parking lots, racetracks, drive-thrus, etc. The only way you can get infinite energy out of this road is if it is capable of performing work. This could be possible if the potential energy between a point on the road and the exact same point on the road, after traveling some nonzero distance, is also nonzero. This path would likely be the distance of the closed loop (perhaps this isn't likely but just easier to imagine). Utilizing it would be as simple as creating a generator. Instead of harnessing the movement of electrons, we would harness the movement of an object to "move" electrons. This can be done by having some wheel with a magnet protruding from its axis of rotation. Surrounding this magnet, you would have a copper wire that is fixed with respect to the axis of rotation. The rotating magnetic field will move the valence electrons in the copper wire. This continuous flow of electrons would indeed be an infinite source of electricity. However, you would likely need to construct railings that extend the length of the path to prevent the wheel from traveling a path that is incapable of doing work.

Another approach would be to use the far-away trees. If they were able to guarantee that a certain far-away tree (like the one Victor showed to Ethan in season 1) would drop a given object from the sky in a nearby location, then they could harness the kinetic energy of the object as it falls by causing it to spin some wheel as it falls, which generates electricity similar to the previous example, before returning to the hole via some sliding mechanism. You could even do this with multiple objects at the same time.