So, let's talk about RF, how to move it around, how to store it, and such.
There's several mods that handle RF distribution/storage, each one takes a slightly different tack, with different merits and flaws.
EnderIO's Conduit and Capacitor Bank system is a fairly elegant way to get RF running around. The advantage Conduits have over other methods is that they can occupy the same block-space as other conduits. So, for example, you can have Fluids, Items, and RF running in the same block-space, which is unique among mods. It also has the Dimensional Transceiver which lets you transport it over long distances wirelessly. The Capacitor Banks have several interesting features besides simply storing RF. First, it can be used directly to charge items needing RF, second it keeps track of and tells you about energy consumption as positive or negative, and third it can form multiblocks for more capacity AND higher throughput. You also have the Monitor which can generate redstone signals based on a percentage of capacity of the bank, which can be invaluable for certain automation tasks. This is why it tends to be the 'default' go-to.
Thermal Expansion goes with a different mindset. It has the least impact on your CPU and RAM of any of the systems, by a significant margin. EnderIO's ability to be compact comes at the cost of performance, TE is very 'lightweight' and elegant. Having said that, the fact that you cannot have FluxDucts in the same space as, say, Fluiducts or Itemducts can really hamper compact build designs. The Energy Cube can be set to emit redstone signal on a few conditions (full, empty, not full, not empty), but it doesn't really keep track of the rate of energy consumption/creation like the Capacitor Bank does, and cannot be set up to emit redstone under discrete conditions like the Monitor can provide. So, better performance, not as many bells and whistles. Plus it looks cool.
Mekanism's system just plain sucks, taking the worst of both worlds. Don't use it.
Draconic Evolution is strictly end-game. By the time you can build it, you've already effectively won.
Now, let's talk about energy creation
Mekanism has several passive RF generation systems. Between the Windmill Generator and the Heat Generator surrounded by lava, you can have a passive RF system for your early-game. Mind you, it won't last you forever, but it's passive, and it's at least enough to get you started into your respective tech trees. Some people call this a huge negative, others swear by it. YMMV. There's also the Gas Generator which has undergone many changes, but can provide mid-tier RF production solutions.
Thermal Expansion has the classic fuel methods, mostly because that was the idea... to create machines and energy production based on the BC model (and as far as I am concerned, ended up replacing it). With that goal in mind, they knocked it out of the park, and has extremely low performance requirements compared to the predecessors. So you've got your 'burning dynamo', your 'lava dynamo', and your 'liquid fuel dynamo that requires coolant' as your mainstays. They then added the Reactant Dynamo, which basically is what you can use to run your mob grinder with since it runs on mob drops and liquid xp. There are no 'passive' RF generation methods in TE, but Lava is so plentiful in the Nether that, once you get a way to pump it from the nether and get it to your power plant, it is effectively so, and typically the primary power system of most early-game Skyblock style maps as a result.
EnderIO decided to take things 'out of the box' with their power generation. Of course, they've got the basic 'burning generator', which (with an Octadic Capacitor) is pretty darn good at what it does. The other generators typically need processing to make what they run off of, you've got the 'liquid fuel burning but needs coolant' one, and you've got one that runs off of Nutrient.
