Just came up with a few ideas I consider fairly clever.
Aqueous Accumulators + Industrial Electrolyzers + Fusion Reactor? Saw that on someone's LP once. And don't forget to have 7x7x8 RC Iron Tanks holding all your Deuterium and Tritium. I eschew iron tanks for giant Xycraft tanks! But nice idea, going in the box.
I feel like something frame-powered. Ugh, frames...
Wither Skellies with normal Generators? Ooh with soul shards, and maybe some golems to finish off after a drop trap, and brain jars to collect XP!
I was going to suggest a frame mechanism with Windmills, a Chunk Loader, and an IDSU which changes location when the Windmills produce insufficient power, but it seems the power of Windmills doesn't change wrt time pretty much permanently. See above
Mystcraft age with a Chunk Loader, Dragon Egg Siphon, and IDSU. Never go into that age. Ever. Now THAT idea has me curious. I may have to boot a DW20 world just that. (I play ultimate mostly, and mystcraft seems to be jacked up on ultimate.)
Be a boss with Bees and set up an Oil farm, and, by extension, Fuel factory. Common, yet difficult, challenge. Done it.
Tier V Nuclear Reactor. Vanilla Redstone, not RP2, to control. Never gone beyond a MkI, I like danger, might have to try.
Bees to produce Uranium, Nuke/Frame machine to mine out the world for resources. Replace the frame machine with a UU machine (or anything else for that matter) and you got a deal.
Scrap. Hhm I see a giant scrap factory full of igneous extruders, recyclers and generators. This would be good for a UU-matter based factory. I might try this first.