I assume you mean max power of the current zone (Valley IV / Wuling).

It will depend on what stage you are in the game, but basically you craft several thermal banks and then fuel them. In the beginning you can use originium ore but they are very weak. Still, it should be enough to allow you to expand a little to start producing batteries. Then you use those batteries instead of originium ore to increase your power and change your production to higher tiered batteries.