How to cast/pull a variable from an adjacent actor?

Hello, I am kind of new to UE4 but have been experimenting, I want to try and make a basic “power system” in blueprints and eventually move it to c++. the issue I’m having is that i cannot figure out how to interact with the “stored power” from a producing object from a consuming object (or a wire later for that matter) I feel like casting is what I need to do, though I heard to avoid it due to heavy performance impact. but i cannot figure out how, or is there a proper way I should do this.
I apologize if this is a badly worded or silly question. but any help would be appreciated, I can try to clarify if needed.