# Does electricity from power generating sources get stored? **URL:** \ **Category:** Factual Questions\ **Created:** [February 19, 2015, 9:23pm UTC](https://boards.straightdope.com/t/does-electricity-from-power-generating-sources-get-stored/713128 "2015-02-19T21:23:38Z")\ **Posts on this page:** 4\ **Page:** 3
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [February 23, 2015, 1:53pm UTC](https://boards.straightdope.com/t/does-electricity-from-power-generating-sources-get-stored/713128/41 "2015-02-23T13:53:23Z")
Additionally, most hydroelectric power plants consist of more than one turbine. They can turn some of them off completely if they need to reduce load. ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [February 23, 2015, 3:40pm UTC](https://boards.straightdope.com/t/does-electricity-from-power-generating-sources-get-stored/713128/42 "2015-02-23T15:40:23Z")
> [@bump](#): > > Don’t the generating plants vary their output to meet the demand? In other words, if they only need 1 mw in the middle of the night, they only spin the turbines at one rate[…] > [@Machine\_Elf](#): > > Yes, but power plants are inefficient when they are operating at less than their designed capacity, and they have to be sized to meet the maximum expected instantaneous demand. So if you’ve got a ridiculous 24-hour variation in power demand, your plant is expensive to build because it’s huge, and the actual instantaneous cost per kilowatt-hour during off-peak hours is high because of the inefficiencies. Power companies try to get around this by smoothing out demand in a couple of ways: > > -build energy storage capacity, or > > -sell off-peak power for less[…] The other thing power companies do is build additional easy-on plants (typically natural gas turbines) that will be powered up only when needed for peak loads. ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [February 23, 2015, 3:45pm UTC](https://boards.straightdope.com/t/does-electricity-from-power-generating-sources-get-stored/713128/43 "2015-02-23T15:45:11Z")
Also, wanted to point out that right now in the US and other developed countries, storage isn’t a big issue for solar power. The peak demand for electricity is nearly always on the hottest days (air conditioners need a lot of power), which is happily the same time that solar generation is highest. And, since most of peak electricity is supplied by plants that are only brought on-line during peak demand, adding solar doesn’t require much change to the base load supply. Now, in the long run, for solar to supply much more of the total, and especially if fossil-fuel heating is phased out, good storage is necessary. But it’s not necessary right now for solar to be valuable and useful. ---
**Author:** ![BubbaDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bubbadog/32/333_2.png) [@BubbaDog](https://boards.straightdope.com/u/BubbaDog)\ **Post date:** [February 23, 2015, 4:09pm UTC](https://boards.straightdope.com/t/does-electricity-from-power-generating-sources-get-stored/713128/44 "2015-02-23T16:09:29Z")
> [@guizot](#): > > It’s still not completely clear to me. When demand for energy is low, does a hydro-electric plant still produce the same amount of energy as when demand is high? If so, is the excess energy “wasted”? Or do they have a way to limit how much energy is produced if there’s no way for it to be used? Many of the power plants remain at a steady output. There is usually one or more plants that are designated as load following plants. These plants have generators that automatically respond to small changes in the frequency of the system. (like a shift from 60hz to 59.9 Hz). Additional load will have a slowing effect on the frequency so the load following plant will respond to a downward frequency shift by outputting more power. Should the load drop it will cause the system frequency to speed up and the load following generator will output less power. [Previous page](https://boards.straightdope.com/t/does-electricity-from-power-generating-sources-get-stored/713128.md?page=2)