I've been thinking about my suggestion more lately. Trying to get a better way to describe what I was looking for.
The goal of this is to deal with a large ship rebuild that doesn't have a reactor on-line.
Jump in, patch the obvious holes on a ship, run the power across the ship with the toggle that @verbal drum mentioned. Now the missing conduits will be easier to spot. With the pumps on, leaks can be more easily found. Much like if you brought on a battery yourself. The difference would be that you would not need to be carrying batteries back and forth from your ship to the derelict as they run dry (or bother carrying these extra batteries on your ship) I can be on an off a Refuel ship in minutes, but when it comes to fixing up a Halberg, or a Lai Bai Gen II, sheeeeesh, I have too many other things to do than watching a battery charge.
My play style goal when I am refurbishing a derelict is to get out of the EVA suit as soon as possible (mostly for roleplay, a bit for pockets)
I completely understand this would be excess fluff for sure, but if the option to ever role-play as your own refueler comes up for this game. Be it a ship requesting O2, N2, power, or anything else that I've personally run out of while flying around and not planning well.... It may be a good addition if simple to add.