4 ms·

Isnt that half of the energy wasted while pumping the water to the higher grounds?

jagger27 8y ago
Better than 100% loss.
NeedMoreTea 8y ago
Pump during off peak, use during peaks. If the wind's blowing while everyone is asleep it would be wasted anyway if you don't find some way to store it.
- deleted 8y ago
  [deleted]
kijin 8y ago
Most of the energy that goes into pumping water uphill can be recovered when the water is released downhill through the turbines. Existing pumped-storage hydroelectric plants have efficiencies around 70~80% which is way better than half. Besides, you get free power if your upper reservoir naturally gets a lot of inflow or precipitation :)
- solarkraft 8y ago
  This is some pretty good efficiency. Lithium-ion batteries are more efficient for sure, but also quite a bit more expensive, I'm guessing. Storing electric energy by just raising some mass seems like a pretty good concept - I wonder why It's not adopted further.
  - ben_w 8y ago
    You need a lot of land and specific terrain; still water isn’t carbon neutral(!); and the nature of the things means that if it suffers structural failure the death toll makes nuclear accidents look like almost nothing. https://www.sciencemag.org/news/2016/09/hundreds-new-dams-could-mean-trouble-our-climate https://www.sciencemag.org/news/2016/09/hundreds-new-dams-co... https://en.m.wikipedia.org/wiki/Banqiao_Dam https://en.m.wikipedia.org/wiki/Banqiao_Dam
    - dogma1138 8y ago
      Lithium batteries are considerably less carbon neutral than physical energy storage when you account for all the energy needed to mine, produce and repurpose them after they fail. While dams have failed in the past if built right they can last for centuries. Also unlike batteries where the majority of the cost sunk is in the batteries themselves with physical storage like this the majority of the cost will be in the construction itself which means that as better pumps and turbines become available you can upgrade your system at a marginal cost.
    - strainer 8y ago
      " if it suffers structural failure the death toll makes nuclear accidents look like almost nothing" You compare a hypothetical dam disaster, with nuclears record so far - its clearly worth reconsidering that comparison. Nuclear plants also consume large amounts of water, and other resources so could not be considered carbon neutral by your own measure. Reservoirs are large lakes, creating them entails ecological disruption but not consumption or degradation in the long term.
      - JoeAltmaier 8y ago
        Not sure where this comparison is going? One dam disaster (Banqiao Dam) caused more death and destruction that almost all other disasters combined. In fact failure of nuclear plants has had remarkably few verifiable deaths. And compared to the energy one nuclear plant produces, dams seem to have vastly worse death-per-benefit statistics. Damming a river can cause ecosystem collapse downstream. That's degradation, as I understand the word. And its definitely long-term.
        strainer 8y ago
        I hoped merely pointing out that discrepancy would suffice - how ben_ws comment compared the history of nuclear accidents to the potential dangers of dams. Potential scenarios are very important in determining probabilistic risk. Simply showing "it hasn't happened yet" is not a valid way to assess risk. This is the reason it costs more to build and keep nuclear plants safe, than it does dams.
  - PaulKeeble 8y ago
    There was an article some months back about a concrete block lifting system that could be used for a similar purpose, but obviously a lot more compact and lower capacity.
  - dogma1138 8y ago
    It has been adopted also flywheel energy storage at scale is by far more common than lithium batteries are today it’s also cheaper and more reliable.
  - KirinDave 8y ago
    Because it scales poorly, is not easy to deploy, and has miserable energy density.
- sambucini 8y ago
  Also Lithium ion battery have a fairly fixed ratio of capacity and power, of about 1MW to 1MWh. That makes them expensive for storing large amounts of power. With pump storage you're much more flexible, just build bigger reservoirs. very large pump storage assets can be optimized even seasonally.
  - dogma1138 8y ago
    With physical energy storage you also don’t need to worry about the environmental effects of lithium nor do you need to worry about charge cycles sure some maintance is required but the majority of the cost is going to be in the reservoir and that can stand for centuries.
JoeAltmaier 8y ago
Pump efficiencies can be from 70-90%. So far from half.

Better than 100% loss.

Pump during off peak, use during peaks. If the wind's blowing while everyone is asleep it would be wasted anyway if you don't find some way to store it.

deleted 8y ago
[deleted]

kijin 8y ago

Most of the energy that goes into pumping water uphill can be recovered when the water is released downhill through the turbines. Existing pumped-storage hydroelectric plants have efficiencies around 70~80% which is way better than half. Besides, you get free power if your upper reservoir naturally gets a lot of inflow or precipitation :)

solarkraft 8y ago
This is some pretty good efficiency. Lithium-ion batteries are more efficient for sure, but also quite a bit more expensive, I'm guessing. Storing electric energy by just raising some mass seems like a pretty good concept - I wonder why It's not adopted further.
- ben_w 8y ago
  You need a lot of land and specific terrain; still water isn’t carbon neutral(!); and the nature of the things means that if it suffers structural failure the death toll makes nuclear accidents look like almost nothing. https://www.sciencemag.org/news/2016/09/hundreds-new-dams-could-mean-trouble-our-climate https://www.sciencemag.org/news/2016/09/hundreds-new-dams-co... https://en.m.wikipedia.org/wiki/Banqiao_Dam https://en.m.wikipedia.org/wiki/Banqiao_Dam
  - dogma1138 8y ago
    Lithium batteries are considerably less carbon neutral than physical energy storage when you account for all the energy needed to mine, produce and repurpose them after they fail. While dams have failed in the past if built right they can last for centuries. Also unlike batteries where the majority of the cost sunk is in the batteries themselves with physical storage like this the majority of the cost will be in the construction itself which means that as better pumps and turbines become available you can upgrade your system at a marginal cost.
  - strainer 8y ago
    " if it suffers structural failure the death toll makes nuclear accidents look like almost nothing" You compare a hypothetical dam disaster, with nuclears record so far - its clearly worth reconsidering that comparison. Nuclear plants also consume large amounts of water, and other resources so could not be considered carbon neutral by your own measure. Reservoirs are large lakes, creating them entails ecological disruption but not consumption or degradation in the long term.
    - JoeAltmaier 8y ago
      Not sure where this comparison is going? One dam disaster (Banqiao Dam) caused more death and destruction that almost all other disasters combined. In fact failure of nuclear plants has had remarkably few verifiable deaths. And compared to the energy one nuclear plant produces, dams seem to have vastly worse death-per-benefit statistics. Damming a river can cause ecosystem collapse downstream. That's degradation, as I understand the word. And its definitely long-term.
      - strainer 8y ago
        I hoped merely pointing out that discrepancy would suffice - how ben_ws comment compared the history of nuclear accidents to the potential dangers of dams. Potential scenarios are very important in determining probabilistic risk. Simply showing "it hasn't happened yet" is not a valid way to assess risk. This is the reason it costs more to build and keep nuclear plants safe, than it does dams.
- PaulKeeble 8y ago
  There was an article some months back about a concrete block lifting system that could be used for a similar purpose, but obviously a lot more compact and lower capacity.
- dogma1138 8y ago
  It has been adopted also flywheel energy storage at scale is by far more common than lithium batteries are today it’s also cheaper and more reliable.
- KirinDave 8y ago
  Because it scales poorly, is not easy to deploy, and has miserable energy density.
sambucini 8y ago
Also Lithium ion battery have a fairly fixed ratio of capacity and power, of about 1MW to 1MWh. That makes them expensive for storing large amounts of power. With pump storage you're much more flexible, just build bigger reservoirs. very large pump storage assets can be optimized even seasonally.
- dogma1138 8y ago
  With physical energy storage you also don’t need to worry about the environmental effects of lithium nor do you need to worry about charge cycles sure some maintance is required but the majority of the cost is going to be in the reservoir and that can stand for centuries.

JoeAltmaier 8y ago

Pump efficiencies can be from 70-90%. So far from half.