Hello, I can't have my grounding pylons to charge in any way, tried many things but nothing seems to work, it always stays powerless, what am I missing ?

Thanks.

Ok finally found, was very simple but not intuitive : it needs to be power generated in the cave itself, not from above. fine.

Thanks for the feedback. You found the intended behaviour: Grounding Pylons need electricity generated locally on the cave depth rather than power supplied from above. I agree that this isn't communicated clearly enough at the moment, so I'll improve the tooltip/status text to make the requirement explicit.