NGU Idle Wiki

Energy Power can be translated into how effective your allocated Energy is. The more Energy Power you have, whether it's bought or from your equipment, and your perks (Generic Energy Power Perk I, II, III, IV, V, VI, final), the more powerful your energy becomes. This modifier affects every feature except for Basic Training and Wandoos (and only the square root of this modifier affects Advanced Training), and is best used combined with high Energy Caps.

Quote from 4G himself (Found by hovering over "Energy Power" in the EXP shop):

"This upgrade improves the effectiveness of your allocated Energy. This means faster progress on features while using less Energy! This will work on Augments, Advanced Training, Time Machine, you name it! Except Wandoos 98, because I said so."

Base Energy Power can be increased using EXP at a rate of 15 EXP per every 0.1 Energy power bought.

Energy Power can also be increased with the Energy power MacGuffin fragment if it is equipped in one of the MacGuffin fragment slots.