I try to stay away from solars for everything except test builds where I need quick, cheap EU that requires no upkeep. Unless we're talking RP solar panels. Then, I abuse those like a ginger stepchild.
Why stay away from solars? For me, its not so much the "fire and forget" nature of them. Its not even how trivial they make power production. I've just never been attracted to 'em. If I'm looking for cheap, powerful fuel for EU, I look no further than geothermal generators. The only machines you need to make em are a crafting table and a furnace. Make a short sojourn into hell and setup a chunk-loaded hell pump, complete with liquid tesseract, and boom. Put the Earth end of that tesseract system on to a big-ass Xycraft tank, and you're all set for power for...a long damned time.
Though, a setup involving Steve's Carts, Factorization, and regular generators sounds...pretty neat, actually. Use conveyor belts (because everything's better with conveyor belts) to transport the fuel into the generators, and there's the makings of a sweet, renewable, completely ecologically unsound (screw the environment!), endless source of EU.
That said, endless energy is something that will always be a thing. People will always, always find a way to completely automate energy production. If you ask me, I think its just plain old human nature. We use power to make things, we want as much power as we can get, and as we all know, laziness is the mother of invention. Well, that and its fun, lol.