I remember seeing a simple design for people in abject poverty to have lights at night: a rock, rope and simple generator. Pull the rock up to the ceiling and then let it slowly come down, generating electricity for about an hour of light.
Now a company is developing a scalable version of this that can power 3400 homes at night. It uses excess renewable energy during the day to stack recycled concrete bricks which can be dropped down the tower when electricity is needed. This version looks ungainly but it works the same way and maybe soon there will be a more elegant model.