Minecraft is never limited in its energy building devices, and the complex machine mod takes the idea of large scale creations which need energy to a whole new level. With lasers, grinders, generators and airships, you harness the power of complex machines to do so much with the game and its construct.
A few of them are rather quite simple, such as the grinder. You set the block down, and then set an empty box above it. This way, you add raw materials into the grinder. It then expels raw energy for your use.
The ocean generator is attuned to local water sources. Within a certain radius, the generator pulls energy from the water thus powering any local objects that need it. It is convenient for those mines which break and fill with water, and it makes for a rather lucrative option of all the complex machines mod for Minecraft. The filler feature fills in areas by self-replicating stone blocks to infinity. This is a great tool for filling in or reaching high areas, while you focus almost solely on other areas of the world.
The laser emitter is almost unarguably the best of the bunch. At its default, a blue beam is emitted from the device. But a series of modifiers are where the laser emitter truly rises. The water bucket mod electrifies nearby water (destroying anything in the water) and the diamond pickaxe will destroy any stone it encounters (making digging all the easier when the laser is created right in front of a series of ever-deepening stone walls.
With all the complex machines available in this mod, it nearly revolutionizes the powering mechanics of the game, allowing you a free reign of destroying, creating, and mining.