Since you are going for your own power system, that will also mean power generation. How about trying to make some of your own unique passive power generation systems. Produce a low amount of RF, but a fire and forget system. Like solar panels/windmills, but more optimised so a large setup of them does not kill performance. One though I had was "Redstone Generator" which is made from a mix of glowstone and redstone blocks (and various materials), which harnesses the natural energy of those two materials in some strange reaction to produce the energy. Almost like a block form of the redstone reception coil component.
Oh please no... Passive power generation is the bane of modded minecraft and should be scrubbed from existance.
I'm talking about solars and windmills, if you can automate a boiler or engines or whatever to BE passive once set up, then fine, but placing a single block and WEE MAGIC POWAH!!! is a terrible concept and should be killed immediately.