Has anybody looked at this idea? Re: damless hydro electricity.

[TheWraith]

Everybody loves hydroelectric power, since it's one of the few forms that's both clean and reliable, but there's a limit to the number of dams we can build. I just had a thought, though, and I don't have the time to do the math myself right now. The kinetic energy of a river is still there, even if you don't build a dam and reservoir, right?

I'm envisioning something like and old-fasioned paddle wheel from a steamboat, tilted on an angle as close to flat as possible to minimize loss of speed from gravity, and one end dunked into the fastest moving part of a river you can find. You could pretty much line a river with these things as long as you can supply decent motors that didn't require high RPMs to pump juice. Think of it as an independent version of an old-fashioned mill wheel redesigned for maximum hydrodynamic efficiency.

Any fundamental errors in my thought experiment that anyone sees?

[gateley]

1. K&R --

[uppityperson]

2. Had friends who moved up to a fjord in Canada, using tidal water moving for electricity.

Had some small thing they were putting into a stream flowing into the ocean that would use tidal water coming up when tide came in.

Kick to mark for later.

[WHEN CRABS ROAR]

3. Lots of small water generators out there based on water drop or

small fast flowing creeks, but none that I am aware of that are large scale.

[SidDithers]

13. Probably bigger scale than you were thinking...

but the Sir Adam Beck Generating Station on the Canadian side of Niagara falls is simply that. A generator based on a water drop. No dam involved, only a diversion of a small part of the Niagara river to go through the generator instead of over the falls.



Sid

[jgraz]

4. you're forgetting the enormous potential energy behind a dam

A dam stores power in the lake behind it. A free-flowing river can't match that kind of stored energy.

However, decentralized power may make some of the paddle-wheel ideas feasible on the small scale.

[WHEN CRABS ROAR]

5. Here in Oregon dams are killing off salmon.

[jgraz]

6. Hey, I'm not advocating for dams. Just pointing out a flaw in the OP's reasoning

It's not as simple as installing a bunch of paddle wheels (which will probably also hurt salmon).

[TheWraith]

16. A dam doesn't create energy, it just concentrates it. The energy is already there.

Just as you don't need a wind tunnel to run a wind turbine.

[GliderGuider]

7. This is called "run-of-river" generation

There are a number of companies out there pursuing variations of the basic concept. It works best in mountainous country where there is enough kinetic energy in the water to make the investment worthwhile.

http://www.straight.com/article-141249/bc-has-8000-potential-runofriver-power-sites-study-shows

[Strelnikov_]

8. Mother of all 'run of river' hydro

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x144140

http://en.wikipedia.org/wiki/Inga_Dam



Most 'run of river' hydro I have seen works essentially like an irrigation ditch. Peel off some of the rivers flow into a relatively flat gradient ditch, and at the point where adequate head differential (potential) has been reached, turn the potential into electrons.


Fall River, Idaho

http://maps.google.com/maps?ie=UTF8&oe=utf-8&client=firefox-a&q=Ashton,+ID,+USA&ll=44.05999,-111.350727&spn=0.01067,0.01884&t=h&z=16&iwloc=addr

Idaho Falls, ID

http://maps.google.com/maps?ie=UTF8&oe=utf-8&client=firefox-a&q=Ashton,+ID,+USA&ll=43.493421,-112.042415&spn=0.010772,0.01884&t=h&z=16

Adel, IA (Abandoned site, made use of stream meander, area near the NE end of the Ped bridge is where the powerhouse is buried)

http://maps.google.com/maps?ie=UTF8&oe=utf-8&client=firefox-a&q=Ashton,+ID,+USA&ll=41.620042,-94.012622&spn=0.002775,0.00471&t=h&z=18


Amana Colonies, IA (Traditional 'mill race')

http://maps.google.com/maps?ie=UTF8&oe=utf-8&client=firefox-a&q=Ashton,+ID,+USA&ll=41.795696,-91.880207&spn=0.04428,0.075359&t=h&z=14

[Dover]

9. Micro-hydro power

Micro-hydro power


Practical Action has developed micro-hydro systems with communities in Nepal, Peru, Sri Lanka, and Kenya.

These systems, which are designed to operate for a minimum of 20 years, are usually 'run-of-the-river' systems.

This means they do not require a dam or storage facility to be constructed but simply divert water from the stream or river, channel it in to a valley and 'drop' it in to a turbine via a penstock (pipeline).

This type of hydro generating thus avoids the damaging environmental and social effects that larger hydroelectric schemes cause.

Cost for a typical micro-hydro system varies depending on the project. As a guide every kilowatt of power generated cost around £800. A 6-kilowatt system, enough to drive an electric mill and provide light for a community of about 500, would cost approximately £4,800. Experience shows that community capital (in labour and cash), financial credit and improved income makes these schemes economically viable and sustainable.
http://www.itdg.org/?id=micro_hydro_expertise

-----------

I'm guessing eventually it will be small yet powerful enough to even place these within a plumbing system (like mini-contained rivers) that work in a closed loop, so that when water flows through your pipes it's also generating electricity. Similar to what's been done in hybrid cars using the breaking system to create extra power.

There was a great thread in the Science forum sometime back (2005?) on this very thing.
A big response to this article that I posted there (not sure what the updated news is on this guy's purported invention, but it sparked a great conversation):


"Tapping into stream power"

07/10 2005:

From The Westmorland Gazette:

Yoghurt pots could spark cheap energy

By The Westmorland Gazette.

A SPARK of inventive genius from a Burneside electrician could lead to a revolution in the way power is supplied "on stream" to thousands of homes.

Ian Gilmartin's experimental waterwheel is the first to harness the hydro-electric potential of shallow running water.

Made partly from "surplus yoghurt pot plastic", the invention is capable of being used in river and stream depths of only a few inches, making it a viable form of electricity generation at up to 100,000 sites across the country.

http://www.beck-mickle-hydro.co.uk/index.php?id=bmh_news

[Beregond2]

10. Well,

you couldn't begin to generate the same levels of power. Think of the pressure of millions of gallons of water behind a dam, and the size and number of turbines that can turn.

[TheWraith]

17. I didn't say you could. But you could build a lot more of them. nt

[madokie]

11. Would that thought be an under shot water wheel you got there?

http://www.waterhistory.org/histories/waterwheels/

I've read about some that are essentially the same as a wind mill except designed for flowing water rather than blowing wind.

[One_Life_To_Give]

12. Still disrupts the natural flow of the stream/river

I have heard that some areas regulate the placement of any such turbine/device. The principal effect is the turbine/wheel/device (whatever you use) slows the flow of water. This causes changes in depth as well as the flow rate of the stream/river. Different species will be advantaged and disadvantaged as these characteristics are changed. So that a stream that was home to Trout or Salmon may no longer be suitable for them and some other species of fish would become dominant in that particular body.

[bhikkhu]

14. Sounds like a water-wheel.

They began to proliferate in Europe after the fall of the Roman Empire, then really took off under the innovative industry of the Cistercian monks in the 12th and 13th centuries. They were used to convert water-flows to manual work, as is milling flower and fulling fabric, but the same energy could easily turn a generator.

No errors, but that river flows are generally seasonal and the EROI should be much lower than the concentrated and comparatively much smaller and more productive generators of a hydro-electric dam.

[Summer93]

15. for small individual homes

I remember reading about a generator that when sunk into a river used the constant flow to generate electricity as the water passed through the tube-like structure. I think it was called a ram.

[stuntcat]

18. I've also wondered..

if it would ever be possible to build something deep in the sea that would get energy from the strong currents or tides or whatever. I think there must be so much power in the movements of the water. Of course they'd have to be built somehow to preserve all the life around them.

The force from water could hopefully be used a lot more.. somehow

[Dover]

19. Tidal Turbines

Tides are caused by the gravitational pull of the moon and sun, and the rotation of the earth. Near shore, water levels can vary up to 40 feet. Only about 20 locations have good inlets and a large enough tidal range- about 10 feet- to produce energy economically. The simplest generation system for tidal plants involves a dam, known as a barrage, across an inlet. Sluice gates on the barrage allow the tidal basin to fill on the incoming high tides and to empty through the turbine system on the outgoing tide, also known as the ebb tide. There are two-way systems that generate electricity on both the incoming and outgoing tides.

Tidal barrages can change the tidal level in the basin and increase turbidity in the water. They can also affect navigation and recreation. Potentially the largest disadvantage of tidal power is the effect a tidal station can have on plants and animals in the estuaries.

There are currently two commercial sized barrages in operations. One is located in La Rance, France; the other is in Annapolis Royal, Nova Scotia, Canada. The US has no tidal plants and only a few sites where tidal energy could be produced economically. France, England, Canada, and Russia have much more potential.

Tidal fences can also harness the energy of tides. A tidal fence has vertical axis turbines mounted in a fence. All the water that passes is forced through the turbines. They can be used in areas such as channels between two landmasses. Tidal fences have less impact on the environment than tidal barrages although they can disrupt the movement of large marine animals. They are cheaper to install than tidal barrages too. A tidal fence is planned for the San Bernardino Strait in the Philippines.

Tidal turbines are a new technology that can be used in many tidal areas. They are basically wind turbines that can be located anywhere there is strong tidal flow. Because water is about 800 times denser than air, tidal turbines will have to be much sturdier than wind turbines. They will be heavier and more expensive to build but will be able to capture more energy.

http://www.eia.doe.gov/kids/energyfacts/sources/renewable/ocean.html



--------------------------------------------------------------------------------


December 10, 2007
Underwater Ocean Turbines Will Generate Renewable Energy
by Jorge Chapa

One the greatest untapped energy resources in the world is the motion of the ocean. And while floating wind turbines and wave-powered generators are being explored throughout the world, there still remains one largely untapped power source, the underwater ocean currents. Well researchers at the Center of Excellence in Ocean Energy Technology have developed what they believe is a technology to allow them to use the Gulf Stream currents that could conceivably cover all of Florida’s energy needs.
The idea is to have underwater turbines placed right in the middle of the Gulf Stream current. The turbines are designed to be about 100 feet in diameter. These will be connected to a buoy that holds the electricity generating equipment. The gulf stream carries billions of gallons per minute, so the impact of these turbines would be minimal if negligible to the current itself.
Now granted, installing all these turbines will take time and significant research, which is why the team is hard at work developing a considerably smaller prototype version that they hope will provide them with enough data to assess whether installing such a system will have an impact in the ocean current, and, just as importantly, all the sealife moving through the area. The prototype will launch in February 2008...>

http://www.inhabitat.com/2007/12/10/underwater-power-generating-ocean-turbines/

________________________________

[stuntcat]

21. I figured..

:blush: I figured I must not be the first one to have that idea.
I'm gonna look at the articles, thanks, it's really interesting.

[Dover]

22. It's news to me too. Your question inspired a google search, and that's what came up.

Your thoughts along those lines were valid and inspired...
great minds think alike.

What we are learning, I think, is that everything is energy and has potential for use and it's just a matter of learning how best to use and transform it. I think one of the simplest examples of this are those tennis shoes that kids wear that light up when their weight shifts during walking or running. That is a transformation of motion into 'light'. What else could simple motion do?

[eppur_se_muova]

23. DUgle "tidal power" turns up 377 results ... mostly in E/E

http://www.democraticunderground.com/searchresults.html?q=tidal+power&sitesearch=democraticunderground.com&sa=Search&domains=democraticunderground.com&client=pub-7805397860504090&forid=1&ie=ISO-8859-1&oe=ISO-8859-1&cof=GALT%3A%23008000%3BGL%3A1%3BDIV%3A%23336699%3BVLC%3A663399%3BAH%3Acenter%3BBGC%3AFFFFFF%3BLBGC%3A336699%3BALC%3A0000FF%3BLC%3A0000FF%3BT%3A000000%3BGFNT%3A0000FF%3BGIMP%3A0000FF%3BFORID%3A11&hl=en

There are actually several approaches. Scotland is home to a couple of big projects.

[FREEWILL56]

20. Gee, do you think that you thought of this or is it you passively read it

from me in a post or 2? In any case the answer to your question is, yes I thought of it.

[silverweb]

24. There are a variety of ways this can be used.

One major project has underwater turbines in the East River generating energy for Manhattan. New technology and better turbines are making this concept quite practical. :hi:

Great article here: http://www.technologyreview.com/Energy/18567/?a=f