There have been requests for this in the past however i recently thought of a way for it to work that might be easier to accomplish codedly. Essentially it would be made with any of the energy storage blocks, better the storage the more storage the transferer will have you then place one in one of the 4 corners that are unnecessary for a nether portal and another on the nether side and whenever you go through the portal it makes it so that whatever energy is in the first one goes into the one on the destination side. Yes this means that in order to get energy from your nether power plant you have to go there and back through the portal (not to mention that your power plant won't work while the nether is unloaded) but it would be alot more fluid then running back and forth with crystals.
On the other hand it would be much easier to start up a base in the nether since you could utilize your existing power structure in the real world.