I have to say that's pretty dumb. It needs a head of 200m and...

  1. 10,662 Posts.
    I have to say that's pretty dumb.
    It needs a head of 200m and the hole is almost 600m. If you matched the 'little' bit of volume in the first 300m at the bottom of the pit with a similar volume holding tank at surface level you would have a massive volume containing the latent energy store. The top tank can cover a wider area with less depth which would provide even more head pressure. Make the top tank 100m deep and keep the pit at max 300m deep and you always have the 200m as a minimum head of water.
 
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