FreeKill

Well you can still automate it through redpower even without minefactory /forestry , and if you do not know how you'd better read it up since it is kinda complex to learn.

RP powered(deployer+filter+ retriever) setup of watermills is the cheapest and most effective choice of infinite energy.Does make your sound bug out and force you to play with 0% volume in game all the time(or remove the soundfile as I did). I have something like 32 watermills per RP setup but I know 45 works just aswell, just like the even 32 more. This setup is ALOT cheaper then all the other. Sure enough filters and timers are annoying to make but the rest is easy as pie. (32*2EU/t = 64EU/t all for the price of 16 generators +3 iron(bucket) and a few sticks)