The dams have to be huge to make it viable. I'd have to go back...

The dams have to be huge to make it viable. I'd have to go back and check my old notes on just what sizes and heights are required but last time I looked it was on a very large scale. Sewerage and runoff have their own issues. Not poo poohing (pun) the idea as i think there was a small vertical generator to be put on one of the cliffside sydney sewerage treatment vertical drops to a outfall ( was it ever installed - years since I heard of it) just saying last time I looked it was so far from being economic and even with grants an impending carbon tax at highest rate so carbon credits etc was not a chance. technology has moved alittle but other barriers remain with the biggest being forsight and commitment by water, community , enviro groups and government authorities.

I think that is how we end up with the desal plants as it is easy to contract and deliver even if they are stupid ineffecient and overpriced etc etc But it is Ok we can run desal on solar during daylight sheesh as a community we really did accept a hospital pass.