First off, i would like to start by saying this is by far my most favorite mod and now on to the suggestion:
The Lightning Rod:
The lightning rod would be a block, or rather 3 blocks high (like a cactus or a sugar cane) that would basically increase the chance of lightning striking on this block. Now what it would do is take that energy from the lightning bolt and transport it through a cable into an MFE or MFS unit (1.12 jiggawats?!?! No, probably like 100,000 EU since lightning is rare and it still would not strike the block 100% of the time) Now you're probably asking "But an MFE unit only holds 60,000 EU?". Exactly, you would need atleast 3 of them to capture one lightning bolt. If you do not.. well lets just say things may overload.
recipe:
[] [] [Iron]
[] [Iron] [] = Lightning Rod. (these stack up to 3 times, each one increasing the % chance of being struck by lightning)
[Iron] []
Now since lightning storms are VERY rare, this probably isnt the best option for power. However with the new Weather-O-Matic, it should be quite the boost of electricity!
The Weather Machine:
This machine would be an advanced machine. It would have to be placed outside (obviously) and have a direct view of the sky. It would require 200,000 EU of power to activate, and depending on what you put in it, changes the weather!
Snowball = snow
Bucket of Water = rain (if you also add a bat-pack it will charge the water, creating a thunderstorm)
nothing = clear skies
Maybe a few secrets too
It could be crafted as such:
[] [Lapisblock] []
[advanced circuit] [Advanced machine] [Advanced Circuit]
[Irrigation TCM] [Uranium fuel ingot] [Freezing TCM]
since it has a uranium core, i feel it should have a chance to backfire, seeing as playing with nature should not be that easy
Feel free to add on to the suggestion