Hydro Power

Hi Guest,

While hydro is (usually) a good idea, and we should certainly tap what we can, it won't nearly do the job by itself. See my previous post here

If ALL of the remaining feasible hydro capacity in the U.S. were tapped, it would total about 6% to maybe 10% of our generating needs.

Source:

International Small Hydro Atlas, Online at: http://www.small-hydro.com/index.cfm?Fuseaction=countries.country&Country_ID=82
Accessed on February 13, 2007

Which country is this, please?

I agree there is untapped potential here. Every hydro dam that I know of (as mentioned in the original post) has a walled in area right below the dam. This is because the water exits the dam at a speed too high for the regular river banks to hold. This un-erodible stretch of river contains the "hydraulic jump" which is designed in to dissipate the excess energy of the water (the energy contained in the shallow fast flow coming out of the dam is significantly higher than the deep slow flow that continues down the river). I've done experiments in our fluid dynamics lab at school to study the effect. Now, this isn't exactly a thesis project I've worked on or anything but I wonder if there isn't some way to have additional, albeit smaller, tapped onto the same flow of water...the smaller ones can be turned on and off according to the swings of demand.

you should check out anything you can find on Gorlev Turbines...

The additional energy available is negligible to the main source and the cost of harnessing it (financial, environmental etc.) may exceed the value.

Keep the question "environmental tipping point" in mind.

Hydro dams rely upon a firm land anchorage at each end, which has to be resistant enough to hold back a considerable lake of potential energy. Normally, they are not easily extended if damaged by shift or seismic disturbance. Naturally occurring excess precipitation can considerably increase the strain on them, while the lack thereof can considerably diminish the dam's ability to provide electricity.

As well as being a resource-intensive project in terms of human resettlement and consumption of construction materials, the building of hydro dams often requires the loss of precious territory for other human interests, such as established homes, farmland, and archeological artifact; while persons settling downstream within a considerable distance of the flood plain originally occupied by the dammed water body are in jeopardy in case of a dam break.

The dam's intakes and spillways physically damage fish and other marine populations, although arguably no more than at naturally occurring waterfall generation landforms. But where the dam has been installed in a gradual stream gradient, the life-cycle process of upstream spawning through the gradient has been replaced by a climb through fish ladder emplacements. These have now been shown to be stressful to the spawning migration as well as to the maintenance of a healthy biodiversity of fish stocks. They have necessitated the establishment of hatcheries to replace the lack of breeding pairs and eventual hatchlings in upstream rivers and creeks.

The stream, pond, wetland, meadow, and woodland ecology of those breeding areas has had to undergo far-reaching changes due to a severe diminishment of hatchling-fed predation and the inability of fishing creatures, scavengers, and detritus consumers to find dead or dying breeding pairs.

[Because other forms of electricity generation are beset with environmental difficulties, I believe the future of electical power generation lies with three main resources: bioreactors, solar energy conversion, and cold fusion. http://ecofriendlypower.wetpaint.com/ is a website with a description of my current work in the bioreactor field.]

Mark

Mark,

I visited your site, and think it is not at all viable for the foreseeable future, and in fact sounds too much like a plan to just draw in investors.

Greg

I don't believe US Environmental agencies or US Environmental groups would allow new HydroPower development. Many other countries are still developing them, notably China.

These companies make part of their living improving the functioning of existing hydro power plants in North America and abroad (as well as new installations)....

American Hydro Corporation (US based) http://www.ahydro.com/index.htm

When I was in the industry 10 years ago they were the best performing hydroturbines followed by:

Voith www.voithsiemenshydro.com (Main plant in US)

Escher-Wyse (can't find them)

There are a few others out there as well....

I think the guest has a point though. We are not optimizing our natural resources usage for power production. I volunteer with several NGOs on potable water projects in rural 3rd world villages and towns. Purification facilities need power and frequently there are polluted streams nearby wherein small hydroturbines can installed sufficient to meet the needs of the projects (or often significantly more).

Given the inconsistencies in delivery of electricity I have seen occur since the switch to an (inter)national grid with the utilities industry and the problems that have occurred in "blacking out" major sections of the country, I favor the idea of local power companies which can be more directly controlled by the citizens. Larger isnt always better, just more cost effective from economies of scale.

Hi Guest,

I think hydro power is actually the best renewable energy.

But, for example, in France we exploit 95% of our hydro capacity and this allows us to run 8% of our needs.

Hi Kedebra , I think that's a little misleading - the remaining 92% is mostly nuclear.

I'm not complaining because it's the only practical way for the foreseeable future. Hydro will not solve the worlds problems for a long time yet. We Brits should have gone the same way. I also believe Superpowers should help third world countries to have and operate nuclear (we can hardly complain of their carbon footprint when we achieved our place on the back of carbo ).The Gulf War was not fought about a load of sand.I do agree with the theme of this thread - much more R%D must be invested in renewables , but the time lag is too great without nuclear.

Agreed, we need to get off of foreign oil.

We should be looking at photovoltaics in my opinion. Hydro has its limits and the fish don't like it. The only problem with photovoltaics is that it needs lots of surface area. There is lots of surface area on residental roofs.

This could be more of an intermediate step. Keep the current grid up, but supplement it with more and more photovoltaics over the months and years until we can phase out some, and perhaps eventually all fossil fuel power plants altogether. We just need lawmakers to "help persuade" everyone to do this.

Then, the only problem will be that people don't like it. haha!

It appears to me that you guys/Gals did not really read what he wrote.

He is basically saying to use a secured drum that float on top of the water of any moving body of water. This drum will be forced to spin by gently moving water.

A stream 8 feet wide could have many/many of these one after another on any stretch of stream/creek/river. Each producing some electricity. A stream a few miles long could have hundred of them with very little if any ecological damage or fish migration damage.

I think this idea needs to be looked at very seriously.

It appears to me that None of you have calculated how much Electricity that this concept could generate. As I am not much on fluid dynamics I don't think I am the person to figure this out. I do understand that the water may be slowed a little at each "station" but I may be wrong.

Tell me why this won't work.

The energy available in a body of water comes in 2 forms; kinetic, from the velocity of the water, and static, the differential height of the water upstream and downstream of the dam. Most hydro plants us the potential energy by converting potential to kinetic through the use of dams, penstocks and turbines. The higher the velocity, the smaller the plant and more energy is harnessed for the cost of construction.

Slow moving water doesn't carry much energy, so you need a large turbine (or "water wheel") which costs more to build. At some point, the cost of construction will never be paid off by the cost of the power produced.

Each component of the system you add subtracts power from the output end. The water wheel turns, but only catches part of the water's energy. The wheen runs the hydraulic motor, but friction and other mechanical inefficiencies will use another 25% of the energy. Then you run a generator, another 25% sliced off.

Many parts of the country also only have hydro potential for part of the year; streams and rivers typically do not flow (amounts significant enough to produce power) in the summers here. So the fossil plants still need to provide power during these periods.

In my region, hydro plants provide an economic source of power to level the daily peaks; fossil plants typically have to operate all day to be available for the 4 hour period when the peak use occurs. Hydro plants can be turned on and off as needed.

You can only generate as much power as you have water; Studies of most bodies of water have already been done, and the "low hanging fruit" has already been picked. The difficult sites, marginal sites, and the isolated sites (no transmission grid) are left, and may never be developed as long as fossil energy is so cheap. It requires significant infrastructure development outside of the plant to tie a small powerplant into the grid. Any one here have $20 or $30 million dollars sitting around? You might be able to provide enough power for a small village. In a wet year.

Micro power plants are being installed in some regions, but unless you are willing to live without electricity for some parts of the year, it will not replace our current systems.

The original post was to have small power plants running on streams. The answer is streams don't provide enough energy to run a pump that will in turn run a generator.

Is that simple enough?

GUEST -the visionary, is proposing something which is the Reverse of the Mississipi Steamer Paddle.

Should work--and Economically too. May be enough power for small communities' needs at River's sides. Could be horizontal shaft with bearings resting on 2 buoys or on 1Catamaran.

With modern Inverter Electronics--- all excess production can be uploaded from these Multiple Floating Stations onto a grid H.T.line.

Decentralize everything - good aim even for Hydro Power Generation ! Sure to win.

I concur with your reply!!! This is an idea that should be investigated.

The general trend among utilities is to build multiple, small generation, local power plants. This would reduce costs for many reasons, and increase profits. But, alas the attitude "not in my backyard" prevails, and prevents this.

Back to the topic. Multiple small hydro power generation units, on many streams, adds up to a lot of power, but maintenance cost also goes up. Shallow depth streams cannot be used because of bottom scour. Direct connect to small generator is better than hydraulic interface, from an energy loss viewpoint.

As to the original post....Placing the proposed generation equipment on spillways and/or overflows could be done.

Thank you #10 (10th responce); Hilltopper here, I live in southern Wisconsin, running thru the town I live in (Janesville) runs the Rock River. There are two dams in town that have been in place for who knows how long (since before my time and I'm 65). One of the dams has a power house on one side of the dam, that at one time was in service,now setting empty. The river is walled in, this is on a part of the river that is not used for anything but an occasional bank fisherman. About two blocks below the dam is a bridge.In that distance several drums could be installed. I haven't clocked the flow (speed) of the water thru this area but it is moving faster than I care to walk,and in some places is over twenty feet deep. Even if one of these drum type wheels that I am proposeing were to only add .1 of 1 percent of the power used in the downtown area alone that would be something that didn't go to foreign oil companies. I know my thinking is skewed and I don't know anything because I don't have a collage degree in anything but, Somebody is going to have to prove to me that this can't work and be profitable.

hilltopper, We need more information.

Did I understand that there were two (2) dams that are intact, one with an abandoned power house? IF YES ~ what is the difference in water elevation on either side of each of the dams? Does the water leave the upstream side over a spillway, if not how? Does anyone have flow volume data (maybe flood monitoring/management)?

IF NO ~ are you talking about the exit raceways with no significant difference in elevation?

There are many small damns that have been "abandoned/de-powered" that are still backing up water but not being used for power generation. This is particularly true in the north eastern USA and the mountains along the eastern seaboard.

One of the oddest thoughts is that the drinking water for NY City probably falls more than 300 feet over its' delivery path. Just think of how much power is in just a 50 foot fall.

Your are right of course "Guest". I did not address his exact question. I can do better.

Its called an undershot wheel. Not really "new tech" dude. It is used by farmers where I grew up to pump water. No drums, just a series of boards nailed together to form vanes, driving a crank. Pretty primitive, but served the purpose of getting water to the cows.

So what turns the drums? Friction against the underside? Vanes? Or will the Weeds and Zebra mussels act as vanes? No Environmental damage? How about shade of the stream bed, the smell of weeds and dead stuff being pulled up out of the water continually, the obstruction of floating debris? Lots of things wrong with it, or rather, lots of things can go wrong, but all fixable if you got enough energy out of it to justify the trouble of going out every other day to clear the weeds from your impeller. The Mennonite farmers all felt that clearing weeds was easier than dipping water every day, or pumping the handle of the pump like they do all winter.

If you got a small stream, use it to grow fish. And eat the fish. If the water is polluted (what are the chances?) use it to grow water weeds that will clean it. Then dry and ram the weeds into logs, and burn the weeds, save big time on fossil fuel. Use the weeds to make the ground fertile, grow oil seed, run oil lamps or generators or cars on the bio diesel. Or ferment the water weeds in big concrete retorts to make methane. But I rather like the streams clear and full of fish instead of covered in big old used oil drums. But thats just me. Your mileage may differ.

It has a serious problem in that it would tend to 'silt up`. The wheel would soon ground.
(About the only problem, albeit a serious one, with hydro power that hasn't
been mentioned.).

I remember reading an analysis some years back, that argued that
this silting will in some cases limit the energy recovered from some peojects to the point
that their costs could not be recovered in 'origional cost uninflated currency`.

There has been some research into this type of power generation in tidal waters, such as the Bay of Fundy. In the last decade there has been some major improvments in the design of low flow turbines but it seems the seasonal flow rates are still a challenge even in sources as high as 5,000 cfs. Ideally low flow turbines could be very productive in areas where tidals waters flow through restricted channels, such as an estuary. This would have to include a lock system for ships but that should not be a show stopper.

With regard to the original comment, I would attach my rotating field (generator) to the axel on the turbine rather than a hydraulic pump. I am sure you would achive greater efficency and much less maintenance. Interesting idea though.

Hydro electricity is so common in Canada that the residents refer to electricity as "hydro". Problems include widespread flooding which leaches mercury out of the underlying rocks (most fish in northern Quebec are now unfit to eat because of the flooding for hydro electricity...this is an area double the size of Japan!) Also, nothing lasts forever. Hydro dams, like all constructions, will eventually have to be replaced. Everybody downstream would LOVE to know your plan! Oh! There IS NO plan! I see.

Another problem is the silting. A stream which is fast enough to carve a ravine will carry a lot of silt. When you build a dam, the silt settles out. Firstly, the silt does not go on to do the environmental job it had been doing for millenia (Egypt's Aswan dam comes to mind) and secondly, the silt fills up the reservoir. Eventually. Apparently many of the dams in BC are now reservoir less because of that. ( A factoid in dire need of checking...I just remember it from an acticle in "Canadian Geographic" a few years ago, and would not be crushed to find that I disremember it..grin!)

And need I mention the results of putting up dams in Russia? I hear the whole Sea of Azov is now a salt-dust bowl. Naah...hydraulic engineering is fascinating, but fraught with more problems than just the blade angle of the turbines!

Lest I seem like a doom and gloom sayer, I should mention that some new ideas are coming out every day to both reduce energy consumption (best bet in the long run) and to make use of lower heads of water like YOUR idea does. Watch these pages! The best ideas in my opinion are ones which reduce or eliminate tramsmission lines. Seeing as how transmission losses may exceed 75 per cent! ( Headlines which give me hope include...Japanese shopping mall uses sunlight brought into offices and stores by fiberoptic cables. Dual level venetian blinds provide shade to workers beside the windows, but allows light to penetrate the caverns of the office buildings. Lighted keys on keyboards allow workers to "work in the dark", reducing eyestrain and florescent light "hum". Ice frozen during winter months is used for AC in the summer. Municipalities are demanding R-2000 standards for insulation in new homes, and houses are now being sited to take advantage of light patterns. Old rubber tires get new life as aggregate in road surfaces. Trash burned in the incinerator generates enough electricity to power the whole town, AND we get to sell the scrap metal.) And thats just off the top of my head.

One of the "low head" (of water) ideas I remember from a while ago is the "ducks". A shaft with racheted off centre floats which would bob up and down like ducks in the waves. You could join them together as much as you like. Cheap, lends itself to mass production. Then there was the "flipper", a sheet of plywood mounted horizontally by one edge under a fishing boat to allow the bobbing of the fishing boat to keep them "on station". (A Norwegian fisherman tired of paying for diesel oil came up with that one!) Of course all these ideas assume your water won't freeze into a 4 foot thick layer every winter.

What about moon power? Could the tide, especially in places like the Bay of Fundy could surely be harnessed...

At the expense of one of the biggest fisheries on the East Coast.....

I would hate to have to give up Digby Mussels in order to power your elecric car.

Using such a scheme in the Bristol Chanel (England) has been debated for years and may well eventually happen. Detail is probably on the www.

Agua doc I have a couple of questions for for if you would please reply.

To all others, in the reality of the oncoming oil crash is building new dams for hydro power feaseable? we are at a tough cross road of what do we do for non-impact power/transportation for the next 100 years?

I am a young person and looking formward in to the future,and I see that smaller rural communites where power production is made locally as will be food and small industry will be the the new life style.

I build communities like these and see the that Soon in the not to distant future we may all live in a 3rd world country.

"Soon in the not to distant future we may all live in a 3rd world country." Only a little behind us in Europe then?

For countries with a high coastline to area ratio ,wave power is much more viable.BBC news this morning reported on the imminent construction of the worlds biggest wave-farm (1 mile off the Orkney isles ).Projected cost is 0.16GBP/KwH compared to 0.06GBP for wind , though this is 'new' technology and costs will fall.Wind farms are socially unacceptable to many.Addressing your initial posting , surely the total available energy from any river is a function of total rainfall in its catchment area.To consider the absurd extreme - flood the entire catchment area and look at the hight of dam that would be required. Rainfall in catchment area *g*dam hight =maximum potential energy.In a real world you could not do this , but even if you could , energy converted to electricity would be a very small %. A string of small dams only mimics one large dam , but with greatly reduced efficiency.