As I understand, IC2 team doesn't have plans to make machine blocks be power wires in the same place.
So I'd suggest, for balance reasons, to make Conductor Upgrade
* Makes machine function like wire (i.e. allows power to pass through
* Wire's power tier equals to machine's effective one (own tier + transformer upgrades)
Pros:
* Allows for more compact setups at the cost of some resources and upgrade slot
Cons:
* I don't know if there are any issues with energy net search algorithm than can show up if power sink would pose itself as wire