What did you use for mid game energy? Im currently running solar boilers but thats only enough for about 32 eu/t and now im looking for a new energysource which can deliver about 150 eu/t renewable.
Also i want to know what you use as a lategame energysource with several thousands of eu/t, gregtech seems to add machines with insane power usage but no way to generate that much...
For renewable mid-game power, most of us do charcoal/creosote because it's so easy. The reason is early-game charcoal is super-easy with coke ovens. And, you get creosote for free as a byproduct. Burn it in an RC LP boiler for some 24/7 energy. Then, burn charcoal as needed in a GT Steel Boiler.
However, there are plenty of other possibilities. Depending up your world and far you want to roam, oil-->fuel is a good power source. If you're a wiz at monster spawners, zombie flesh turned into methane is a good one. If you're into eIO, hooch or fire water are good ones. If you're into bees, a fairly early one is coal. Not long after is oil (fuel).
If you're heavy in Thaumcraft, there are ways to make charcoal and other things like gunpowder.
Minechem has its own way of generating power.
But, the most straightforward, linear path for many is:
1. coke oven
2. tree farm of some type
3. burn all that lovely creosote in RC LP boiler
4. get enough steel to make a GT steel boiler and burn charcoal on demand
That will make enough steam for mid-game. To turn steam into power, most of us use RC Steam Turbines to make IC2 EU, then we transform into GT EU using GT Transformers.