Earlier today I was building a secure anti-nuke bunker- accessible only via teleport and running off a combination of dedicated solar power lines and nuclear power when it occurred to me that if we can pay energy to teleport mass, why can't we teleport energy?
Ideally this would be a top tier energy converter- maybe made of a teleporter and a HV transformer or something along those lines, which would take power from its input faces and teleport it out its output face to a linked Power Beamer.
Obviously these machines wouldn't work for people, but otherwise they'd function similarly to teleporters allowing for the transfer of energy over large distances where massive wiring arrays would otherwise be impractical.
More importantly, such a device would allow for the use of truly 'closed' bunkers or the like, receiving exterior power from secure sites.