Could A Hydroelectric Power Station Be Created Out At Sea?

[crankfwd]

Okay, I've got another idea about hydroelectric power that I could use some help with. Imagine you have an enormous funnel that is 1km in diameter at the top. This enormous funnel is held in place by four hollow towers (that are open at the top), that are cemented into the sea bed. The top of the funnel is just below sea level so that it is always half full of seawater. The spout of the tunnel goes about 250m down, where it splits four ways into tubes that feed the four hollow towers. Where the water feeds into the tower there is a hydroelectric turbine. The water keeps on falling after going through the turbine and falls into the hollow tower

[crankfwd]

...(sorry, cut myself off there) the water falls down the tower, the inside of which gets narrower until they hit another turbine which is used to drive a propeller which helps the falling water get pumped out to sea. My real question is, could the water get up enough speed that it could be, with the aid of the second turbine, be pumped out at the sea bed?

[douglas9401]

If the top of the funnel is just below sea level it wouldn't it always be completely full?
Wouldn't the tubes just fill up too?
Could the turbines cope with all the dead fish and salt?
Why am I typing this stuff?

Why not concentrate on developing tidal power?

[alavahalf]

If I were you I shouldn't spend a lot of money on this .. your 'funnel just below sea level' would either be swamped or starved of water all of the time.
Assuming you haven't considered the rise and fall of the tides.
It will be money down the drain.

[ToraToraTora]

don't mess about, stick a series of large turbines in the straights of Gibraltar, that'll capture the tidal energy of the med.

[Dee-M-See]

STRANGFORD LOCH IN IRELAND HAS ONE
DONT KNOW HOW SUCCESSFUL IT IS

[Captain2]

Don't think you'll make much power with that TTT. ;)))

http://adsabs.harvard.edu/full/1963IrAJ....6...12M

[ToraToraTora]

"the inward current can be traced ads far as crete" - I'd say there is a fair amount of water movement there.

[crankfwd]

Douglas-the funnel height could be adjustable, so it is constantly just half full. Maybe some netting to keep the fish out and the turbines made of plastic. Tidal power is rubbish, I'm thinking Hoover Dam levels of power from each tower. Yeah, I'm worried that the towers would just fill up with water, that's why I need a way to get the water out.
alava- it would be right out to sea, so not affected by tides as much and don't intend to spend any money just wondering if it is feasible(but appreciate the money down the drain pun)
TTT-again tidal power is pants. But judging by your thumbnail you just want to start another war with a Spanish speaking country.

[ToraToraTora]

"TTT-again tidal power is pants." - Really? a huge mass of water is moved around the globe every day, think about harnessing that.
"But judging by your thumbnail you just want to start another war with a Spanish speaking country. " - this section called science, it's where we talk about science. Which is why we try to humour your crackpot non schemes with at least a facade of sensible discussion.

[crankfwd]

Dee-Strangford Loch is tidal but pretty good and supplies 1500 homes with electricity. Hoover Dam provides a million homes and that's the sort of power I'm looking at, although it has 17 turbines so I would need 17 towers to match it. The main problem is getting the water out of the towers. I'm thinking the second (lower down) turbine driving multiple exit pipes with propellers and one way valves. Anybody know if that could work?

[crankfwd]

TTT- whoa there! I was just joking about the thumbnail, got no problem with your politics. Just think that Spain might object to anything involving Gibraltar. Also, when I say tidal is pants, I mean in comparison to hydroelectric, nuclear and even coal power. I have full respect for tidal but just like wind power, I don't think it will be enough to replace coal. So please accept my apologies as nothing personal was intended. Also, crackpot? These are my most sensible ideas, so please continue the facade.

[New Judge]

You'd have to pump as much water out of the towers as went in them from the funnel. Net gain therefore equals nil (minus the losses in transmission).

[crankfwd]

New Judge- that's why I've got two turbines in each tower. The first to create electricity and any power from the second lower turbine would all be used for pumping. If the towers were far enough out to sea and the towers deep enough, then could even manage three turbines.

[Peter Pedant]

you should be able to mock this up in a washing up bowl
and persuade yourself it wont work

a lot of this is occurring below sea level - so the water wont fall anywhere. - it will tend to go the other way

anyway you could do this in a bath tub and show / verify/ see it is a non starter

[Peter Pedant]

if you have time on your hands
read Carnots reflections on motive power of heat

no equations - 150 y before Hawking he said " equations put people off". at least at the end you can say that you ahve a perfect working knowledge of carnot's ideas
rather than you have completely wasted your time

his proof of the first law of thermodynamics is classic
"if you could get energy out of nothing - someone would have done it before"

[Peter Pedant]

really good ref Cap'n thanks
a really good ref considering the wall to wall twazzocks we have had over Dom CUmming - oh lardy lardy!

[crankfwd]

PP-thanks for the Carnot rec. I'm thinking that even below sea level, the water should fall as long as the top of the tower is open to the air. It's just getting the water out of the bottom of the system before it can rise up again. Also, I'm not trying to create energy from nothing, I'm trying to get energy from gravity, like the Hoover Dam, but out at sea.

[ToraToraTora]

crankfed; " Just think that Spain might object to anything involving Gibraltar. " - why? Gibralar is British, besides it was just one example of many tidal currents that could be harnessed. "Also, when I say tidal is pants, I mean in comparison to hydroelectric, nuclear and even coal power." - How much energy do you think it takes to continually transport 50% of the worlds oceans around the globe. "I have full respect for tidal but just like wind power, I don't think it will be enough to replace coal." Probably not but it is there and could be harnessed to a greater extent than it is. "So please accept my apologies as nothing personal was intended." - accepted. "Also, crackpot? These are my most sensible ideas, so please continue the facade." - You're the sort of chap that if he was marooned on a desert island and found a boat would break it up to make a raft.

[bhg481]

crank - what makes you think the tides have less effect out at sea. Tides are just as high in the middle of an ocean, it's just that you've nothing to measure them against. It's the moon that attracts the water and it has exactly the same effect out at sea.

[New Judge]

//I'm thinking that even below sea level, the water should fall as long as the top of the tower is open to the air.//

Why should it fall? Where's it going to fall to? Get your mum's washing up bowl, fill it with water, put a funnel in it, sprinkle some pepper or something into the water within the funnel (so you can track just that bit) and see if it falls.