Question Hydro electric generation.

[jinglesassy]

Hello, i recently watched a documentary on the Hoover dam and it got me thinking. Why instead of building huge multi billion dollar dams that change the surrounding environment in drastic ways. Why not just drill down a lake around 1000 feet and put the generators there? Huge more amounts of electricity from the huge amounts of water pressure increase and it will always be there as long as there is rain. Also it wouldn't change the environment in such drastic ways.

 

[SiberianTiger]

Simple: you need a water current to draw energy from, not just a static amount of water. Where the water from your lake would go and what would you be replacing it with?

 

[Urwumpe]

Also, the drastic ways depend also on how the dam is planned. Not every new large lake is a disaster, unless you believe that environment protection means, that the world should cease changing.

There are good and bad examples.

 

[jinglesassy]

Yes but stopping huge rivers kill almost everything down stream of it and kill alot behind it too. Wouldnt this stop it while still producing alot of energy for the grid?

 

[jedidia]

You need FLOWING water to generate electricity. The water's got to do some work which you can harness. A static mass doesn't do any work. Rain won't be nearly enough to provide you with enough water to keep a steady output.

 

[jinglesassy]

So make a pipe going down a bit more and forward to the generator to get the flowing water.

 

[Urwumpe]

Not only the water needs to be flowing, you also need to remember that a reservoir is not infinite - once the reservoir is full, you need to open the dam to let as much water flow out, as flows in.

The damage caused by dams downstream is differently - for example, if regular flooding doesn't happen, farming goes down the drain. Also, dams for supplying water to farms, (not electricity) can make the places downstream much more arid - that is the current conflict between Turkey and Syria.

 

[jedidia]

So make a pipe going down a bit more and forward to the generator to get the flowing water.

and where, pray, did the water come from, and where does it go, if not from a river into a river?

 

[jinglesassy]

and where, pray, did the water come from, and where does it go, if not from a river into a river?

Like the great lakes? Or the ocean?

 

[jedidia]

Water usually gets from lake to lake and eventually into the ocean by rivers

And you still haven't solved the problem of where the water is supposed to be comming from.

 

[SiberianTiger]

Also, dams for supplying water to farms, (not electricity) can make the places downstream much more arid - that is the current conflict between Turkey and Syria.

As well as between Uzbekistan and Tajikistan: if the latter build a power plant upstream, that would make lands of the former arid.

 

[Artlav]

The ocean could actually be an idea - what if we put generators across panama joint? The levels of atlantic and pacific differ at that point. I wonder if that would be enough.

About the lake and pipe downstream - what goes down won't come up on it's own.
And there is nothing below the ocean to drain to.

 

[jinglesassy]

Well the ocean is deep enough that we should just be able to put a specialized generator at the sea floor right?

 

[SiberianTiger]

Well the ocean is deep enough that we should just be able to put a specialized generator at the sea floor right?

No, it's like connecting only to a "+" of a DC power. You light bulb won't turn on. Got it?

 

[jinglesassy]

Um what? What are you trying to say siberiantiger?

 

[SiberianTiger]

The ocean could actually be an idea - what if we put generators across panama joint? The levels of atlantic and pacific differ at that point. I wonder if that would be enough.

How much do they differ in level? In my idea, much less than daily level change due to tides, so employing tidal power is more sound and does not require trans-continental pipe-ways.

 

[jinglesassy]

So you are talking about that snake like thing that generates power from tides? This thing

http://www.waveenergy.ie/images/OPD.jpg

 

[SiberianTiger]

Um what? What are you trying to say siberiantiger?

I'm trying to say that if you want to turn on a light-bulb powered by a battery, you have to make a closed circuit between the battery's "+" and "-" poles. Current will the flow from "+" to "-" and on its way make work in your light-bulb, lighting it up. If you break your circuit, there's no way for the current to flow through, and no energy can be drawn from the battery.

Imagine water reservoir (upstream of a dam) is your wire attached to "+", and the river flow downstream is your wire attached to "-" of the battery. Your light bulb is the hydro power plant with all the consumers attached to it (who dissipate energy). Your battery in this case is actually Sun, which makes water rise from seas to intra-continental areas and on top of mountains in form of rain and snow.

If you let your current flow, by opening the water locks, you get the stream you can use to draw energy from. If you break the circuit in one way or another, no useful work can be done then.

(if you remove your dam and just put your water wheel into river, that might work, but power output is really tiny)

Straight analogy here.

 

[Urwumpe]

Um what? What are you trying to say siberiantiger?

Shall I make you a small Inkscape drawing to explain basic physical phenomena like potential and kinetic energy, or do you just believe us, if we say that you need to be able to make water flow from a higher level to a lower level.


A tide power plant at panama could be interesting, like a large narrow fjord, if opening towards the Atlantic...tide ram pressure power plant...:lol:

 

[jinglesassy]

And there is a current in the oceanic water currents.