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Homework Help: Calculate the area of water suspended at 500m to produce 23TWh

  1. Nov 16, 2016 #1
    • Thread moved from the technical forums, so no Homework Help Template is shown.
    Calculate the area of water, suspended at 500m, needed to produce 23TWh of energy
    I've done a calculation but the answer seems far too small
    If I needed to store the UK's supply of energy for three months i.e. 23TWh of energy
    in a reverse pump hydro storage at an elevation of 500m

    I've got an answer of 395m x 395m if the water was 30m deep but this seems way too small.

  2. jcsd
  3. Nov 16, 2016 #2


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    Homework Helper

    How did you get that? Your answer is about 1250 swimming pools which would last 625 people about a year or 2500 people 3 months (assuming about 5.5 MWh per person per year). There are like 64 million people in UK so you need lots more, like 160^2 times more.
    Edit I was looking at the 3 months maybe 85^2 times more for 23 TWh which is less than the 88 TWh I assumed.
    Last edited: Nov 16, 2016
  4. Nov 16, 2016 #3


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    Science Advisor

    I think that amount of stored energy is 23*10^12 J, or 23 TW-s, not 23 TW-h. You forgot the 3600 seconds in an hour, which will make the amount of water needed 3600 times larger.
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