1.7.10:
(started modded minecraft in 1.6.4, and never got around to doing a "proper" non-cheat world in 1.6.4)
Steam engine(RotaryCraft) with lit netherrackas heat source.
fuel efficiency: infinite, as renewable(netherrack burns forever, providing a steady 140°C, water can easily be pumped even if you only have rotarycraft, it has a pump and fluid transfer)
efficiency: ++++(it is quite cheap to make for its power, and doesn't need fuel)
powerful: medium-low(for rotarycraft, anyway, you need for of them to power a grinder(no gearboxes), power equals 31RF/t or so)
summarized cost:
- 3 cobblestone
- 1 gold ingot
- 12,66666666666666666666(and so on) HSLA Steel(that is an average batch of nine iron in the blast furnace, with coke, maybe a bit more)
Hydrokinetic Engine(RotaryCraft), 64 block waterfall:
fuel efficiency: infinite due to crappy minecraft fluid physics
efficiency: ++(quite expensive to make, and requires complex setup to get it, as it requires spring steel, which needs a blast furnace heated to 1150°C, which is hard to get without the hydrokinetic engine. also needs 3 diamonds per engine, and the waterfall is a b*tch to make, but it is efficient)
powerful: +++, it beats essentially all uranium reactors not using active cooling(aka condensators or this coolant cell thingy where you take cells out, put new ones in instead and then have a bunch of reactors dedicated to cooling the coolant cells down again), with about 250 effective eu per tick, and if you turn it into RF, you will get about 1kRF/t. in Rotarycraft power, it has an output of half a MW, and you need 8 of them to run the extractor, which is more of a mid-game machine. do you have any f*cking idea how hard it is to get the power of 8 hydrokinetic engines into one extractor without bedrockium gearboxes?
I also use DC electrical engines from time to time(aka for blowing items around with fans), which are basically redstone engines that can actually be USED for stuff other than pumping, although they generate only 1RF/t, and have used AC electrical enginesand performanceengines in the effort of getting a friction heater to more than 1150°C. AC electrical engines use magnetized shaftcores(done in the magnetizing unit, which uses power), to generate power every time they get a redstone pulse(clocks for the win!). They are decent, but having to magnetize shaft cores again and again and again is annyoing(they demagnetize while being used). Performance engines use ethanol plus additives, aka redstone, gunpowder, and blaze powder, blaze powder being the most efficient, redstone the least efficient. while they are probably quite simply to automate, it is simpler to spam hydrokinetic engines, and so i have really only used them to get spring steel.
EDIT: for some reason, my space key ignores input from time to time, aka there were a few spaces missing. now they don't miss anymore. DUN DUN DUUUN.
EDIT: messed up hydrokinetic engine power output. got the EU right though.