Your first generator in kenshi will be a wind mill, but you will not get battery technology until much later.
This is a problem, because depending on base location, wind is not constant. Places with constant wind, have very poor soil for farming.
this means that a farm base will not have constant power unless it is in a very fertile location.
Chances are very good that your first base will be in a tough location.
Your primary use for power, is not lights, or tech, but for advanced wells. Not only are they automated, but they produce far more water then the hand operated well. You can not survive without them. But when the wind dies, it can be gone from 3 days, to a week, so you will not have access to water for your farms.
So how do you get around inconsistent power? the water tower.
At 3 building materials, the water tower is a cheap building to make. the best part of this, is if you have a source of water away from your farms, you can put the water tower near your farm, and cut farmer transit down. More importantly, you do not have to be constantly hauling water to it. once you hit a comfortable water level in the water tower, you can safely turn off the wells if you wish to. That way, you can conserve power, and move that worker to another task.
Then again, hauling large quantities of water will level up athletics AND strength. Meaning that after a bit, your water hauler can run to town, buy a bunch of stuff, and run back home in a few hours. Or gain the strength needed to wield a fragment axe, the 2nd most dangerous class of weapon in the game.
Though once you hit that point, you should have enough crops to consider a bio fuel distillery, that way you can run a diesel generator for when the wind dies. This is important, for when you want to get higher level tech, or start brewing alcohol for trade goods.