I think you have hit the mark by pointing out that there;’s nothing for them to gain from doing it. So the answer would be to give them some incentive. How about charging them rent for the space for the entire time that you have been there and into the future. Calculate the rent on the basis of commercial storage and lost opportunity to use the space for your own purposes. Add in the incentive that you won’t charge for back rent if they move the power board.
By the way, the chances are the power board is past its use-by date anyway and a more efficient solution might be to install a completely new one in the alternative location, then just wire it up when it’s ready to go. Minimum disruption, maximum benefit.
What does anyone else think?