MoPower is a mod centered around power generation and storage. It has things such as giant steam engines/accumulators and implements wind turbines and nuclear reactors.
Nuclear Reactors: Ever wanted a clean power source? Well nuclear reactors are your friend! They are the cleanest and most powerful of all the green energy sources. But they require quite some setup and are slightly hazardous to your health.
Wind Turbines: Power your factory with the power of the wind! Just a warning. Like the green energy of the solar panels, wind power isn't very reliable for a primary power-source. (I recommend MoWeather alongside these.)
Burner Thermal Generator: Power your factory by burning coal and getting electricity directly from it! Save on space, by not using big bulky steam engines or water pipes.
Octo Accumulators: Basically Giant accumulators. Not much I can say.
Operation of Nuclear Reactors:
First you mine the ore then, refine it into usable nuclear rods.
And with those rods you put them into your nuclear reactors along with water and out you get super-heated steam.
And with that steam you just send it to your steam engines.
You also get nuclear waste as a by product.