Nearly lossless power teleportation with Infitech 2:
Ingredients:
(1) Two GT battery buffers of an appropriate tier (usually MV or HV).
(2) One GT transformer of an appropriate tier (MV or HV).
(3) Two IC2 power storage blocks (CESU, MFE or MFSU)
(4) At least one IC2 power storage item (RE Battery, Energy Crystal or Lapotron Crystal)
(5) Two BluePower Retrievers
(6) Two Thaumcraft Magic Mirrors
(7) Some EnderIO conduits
(8) Two EnderIO item filters
(9) Two chests
The basic idea is to pull full power storage items out of their power storage blocks connected to a power producer, send them through a magic mirror and insert them into a power storage block connected to a power consumer, and when they're empty, pull them out of there and send them back through the mirrors to the power producer to be recharged.
This idea had to overcome some difficulties. First, you can't pull GT batteries out of their buffers, which is why you need the IC2 power blocks and one additional GT transformer on the power consumer side, which is why this method is only "nearly lossless" compared to a theoretical set of two power teleporter blocks directly connecting the two buffers. The additional loss added to what's inevitable when power leaves a GT block depends on the tier but is less than 1% for HV voltage or higher.
Second, while it is possible to pump items into a Thaumcraft mirror (the Thaumonomicon says so, it's no secret), a conduit will not pick up items pushed from a mirror in front of it. For that reason, you need a BluePower Retriever to pick up the power storage items coming out of the mirror, and since the transport is two-way, you need one on each side. I hope to overcome this problem in another way, since it doesn't look elegant, but so far it's important that it works.
Here's a picture of my test setup:
This setup has used MFEs and using one energy crystal going back and forth, has successfully transferred several million EU contained in the HV x4 battery buffer at the right end to the HV *4 battery buffer on the left end. You need to use colored conduit lines on the EnderIO conduits and the filters need to be set to "match metadata". I tested this with advanced filters but found I don't need them since the energy crystals store their power as damage values and not as NBT data. A simpler setup without the mirrors and retrievers and using only the conduits and one buffer chest can be used to transport power with little loss over medium distances, removing the restrictions GT power loss imposes on the design of your base.