# Calculate the area of water suspended at 500m to produce 23TWh

1. Nov 16, 2016

### HorseRidingTic

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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
using
P=mgh

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

HorseRidingTic

2. Nov 16, 2016

### lurflurf

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
3. Nov 16, 2016

### phyzguy

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.