There is no part of an EV, or most anything else, that’s not important. If it wasn’t part of the whole, it wouldn’t be there. You might be killed in an automobile because of its poor design or because a cotter-pin fell out of a steering knuckle.
Hydropower is a great resource for those living offgrid. It doesn’t have to be hydroelectric either, water power provides constant power and his high torque – you just need to ensure your stream has the right combination of flow and head and your turbine is designed to maximize the energy contained in the water.
Basic Information Multi Purpose Power Unit with Horizontal Water Turbine is a PDF from the CD3WD set and discusses a proven setup used in multiple villages to run mills and oil expelling presses for community agriculture.