Energetic Sheep allows you to collect energy from electrified sheep. They can spawn naturally, which is pretty rare, or if a normal sheep is struck by lightning it will turn into an Energetic Sheep.
The wool they drop can be used to power machines or whatever you may need energy for. You could kill the sheep for one time energy harvesting but the more beneficial route would be to simply farm and sheer them as you would any standard sheep for wool.
But be careful, though, as the dropped wool can zap you when you pick it up! And the level of energy seems to vary depending on the color of wool that is dropped.
In order to really take advantage of shearing these Energetic sheep for maximum energy output, this mod comes with Energetic Sheers that automatically stores the dropped wool without risk of electric shock! They can be used to shear Energetic Sheep or anything else you’d use shears for except that these run on energy rather than durability.