As another commenter pointed out, hydroelectricity can compensate for fluctuations in other types of renewable energy. Pumped storage power plants (a form of hy

As another commenter pointed out, hydroelectricity can compensate for fluctuations in other types of renewable energy. Pumped storage power plants (a form of hydro where you use gravity as a gigantic battery) can also help smooth out any remaining fluctuation. This could, however, change the balance of power between different regions of the world. Fossil fuels favor coastal flatlands where it's easy to transport bulk materials. A civilization that depends on hydroelectricity, on the other hand, might favor a more mountainous terrain. The capitol in the postapocalyptic world of The Hunger Games is located somewhere in the Rocky Mountains, powered by hydro. Our usual concept of business hours might also have to disappear, if we're going to rely on hydro to smooth out fluctuations in other energy sources. We may no longer be able to afford peak usage at certain times of day, and therefore spread out power-consuming activites across all hours of the day and night. This helps eliminate the rush hour, which is itself a terrible waste of energy. If push comes to shove and we need to ration power, I suppose this will put more pressure on battery technology. People will have to store up on power at certain times of the day, and use it until the next charge-up time. It will be a bit like fetching water from the well every morning. But even under such circumstances, some people are clever enough to put a tank on the roof and install pipes/faucets to simulate a constant water supply. Batteries are to an intermittent power supply what a tank is to an intermittent water supply. We as a species can't tolerate inconvenience. We'll find a way to make life as convenient as possible, no matter what the circumstances. Intermittent meat supply? Brb, gonna store up on ham and bacon during the hunting season.