Is it theoretically possible and/or economically viable to construct batteries capable of supplying an entire city with electricity for a day or two?

One of the big problems with power plants of any kind is waste motion. The turbines keep churning, the head of steam continues to form, during the off-hours. If we could somehow store all that energy for later use, we would need a lot fewer power plants, and would be able to spare a lot of resources.

Is anyone working on this, or is it just not worth it? Would batteries of this kind do more harm than good?

  • $\begingroup$ Ill also add that, in addition to the inefficiency losses at the power plant, and transportation energy from the power plant, electricity is like heat- it constantly "leaks" over time (like a cold can placed in a cooler within a hot room). $\endgroup$
    – OnStrike
    Commented Nov 26, 2015 at 4:34
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    $\begingroup$ "The turbines keep churning, the head of steam continues to form, during the off-hours." Mostly wrong. Look up the different kinds of power plants and their roles, look up pumped storage. Also vote to close for now, no prior research. $\endgroup$
    – mart
    Commented Nov 26, 2015 at 6:22
  • $\begingroup$ You know that some power plants don't have any motion at all, right? Even more don't have any steam. And the ones that do have steam can typically be kept on warm-standby at a tiny energy cost. The big exception is nuclear; and France demonstrates how to manage that challenge. If you'd like to ask specifically about that, you can always drop by chat and ask for help in putting together a well-formed question. $\endgroup$
    – 410 gone
    Commented Nov 26, 2015 at 7:56

1 Answer 1


Yes, it's theoretically possible. But it wouldn't necessarily be any more efficient than the current power plant method.

The battery is just the vehicle to store the potential energy. But the energy being stored has to be created in the first place before it can be stored.

This is the same reason why electric cars are not necessarily "green" in all cases. Yes, the electric power comes from a charging station. But the charging station has to get that energy from somewhere. And if the power comes from a power plant converting hydrocarbon fuel stores, well then there is no reduction in overall hydrocarbon emissions from using the electric car. The emission points have merely been redistributed.

  • $\begingroup$ It is a valid argument as far as coal-fired plants go. When the demand goes down, the amount of coal fed into the furnace can be reduced. But the dam turbines continue spinning at the same rate around the clock. ... I absolutely agree with you on electric cars: the whole idea is absurd; it's a clever marketing stunt, no more. $\endgroup$
    – Ricky
    Commented Nov 26, 2015 at 2:26
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    $\begingroup$ @Ricky: Hydroelectric power plants store the excess energy created during periods of low demand for later use during high demand periods. A common method is called pumped storage. Pumps pump the water in the resevoir below the turbines to a point above the turbines for storage. Then, when extra power is needed, valves release the extra water through additional conduits which increases the water flow volume at the turbine, thereby increasing its rotational velocity and power output. It's a mechanical battery. $\endgroup$
    – Mowzer
    Commented Nov 26, 2015 at 2:36
  • $\begingroup$ Yes, I am aware of that. It is a commendable effort, but it's not what I asked. $\endgroup$
    – Ricky
    Commented Nov 26, 2015 at 2:45

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