Future Energy Sources 1.5 Hydroelectric Power

Masu asked: Can we use less damaging technology like the micro hydroelectric in stream systems to reduce or dependence of fossil fuels?

I think we can, provided we also moderate our energy demands to a reasonable level. Hopefully I'm about to put my money where my mouth is. We are looking at a property which has a stream running through it. I don't know any details yet. Saw the property listed on internet and it's 500 miles away. We plan on visiting it next week.

Being located outside of any town with restrictive bylaws we expect to be able to build some demo projects. I intend to attempt to utilize all the energy saving techniques I have learnt over the past 30 years. Can't say yet if location lends itself to wind solar or micro hydro generation. Being an acreage we may also be able to have a flock of chickens and then attempt a methane digester on a small scale. I do not expect I will become energy self-sufficient but if I can reduce my dependence on buying energy from elsewhere it will still be a sucess.

Elnav

Hi elnav, You are right! They have used this technology in Norway for the last 60 years, Small coastal towns use the local rivers. Where I lived in south Norway they had three small power stations on the same river, each was ten kilometers apart and they used francis turbines in each. The total fall was about 110 meters over a length of 40km. They produced enough power for 20,000 homes, 62 shops and 16 factories.

Economics of scale suggest that a large volume of things can be made or done at a significantly lower unit cost than a small number. Solar PV would benefit more from this than small-scale hydro, because many more potential sites for PV exist. Also, small hydro requires more skill and knowledge to implement, let alone any permits or other regulations that the governmental agencies may have.

I recall reading that most large-scale hydro sites have already been developed, so small-scale is the area with the most growth potential. Perhaps the development of 3 or 4 models which can be applied at different heads and flow rates would allow sufficient ease of installation.

Balance seems to be key: Energy need to energy availability, energy desires to energy costs, environmental impact to future environmental degradation, etc.

Other types of small hydro include units anchored in a moving stream or river, low-head wheels, and more.

--John M.

Congratulations for stimulating ideas that could energize individual homes at point of use. A list of Cost effective suppliers of actual generators with prices and specs would be of interest. Perhaps a list of interested parties could gointly arrange whole pricing for small home projects.

On another scale, however, never once believe the hoax that existing large dams are fully utilized globally. TVA alone has extreme water potential in a series of dams collecting water hydro potential in nine states. The TVA Raccoon Mountain site is the Only one of those TVA dams that is equipped with multiple generator/pumps. During spring rainfall much excess water is wasted over the top but only the one is utilized to pump water into the dam at night and during idle generation. Think of the lost generation capability not utilized from solar, wind, nuclear, and even fossil during underutilitze periods of potential low cost generation.

Meanwhile, TVA demand increases 600 Mw per year - a good sized unit of a power plant needs to be added annually. TVA wants cities and users to grunt the money for adding the capacity. TVA however, is not interested in allowing cities to utilize existing dams as pumped hydro storage for solar or wind generation. History wise, TVA confiscated some of those dams from Alcoa Aluminum, for example, rather than allow private enterprise to fully develop the facilities.

Perhaps a list of interested parties could gointly arrange whole pricing for small home projects.

I remembered somebody mentioning a company in India that specialized in the supply of micro-hydroelectric power generating systems but unfortunately I have been unable to find the reference. Somebody else may be able to find the reference though as it was in a CR4 discussion within the last three months. I did however find a page that talks about micro-hydroelectric systems that people may find interesting.

I agree with the balance, I am from Idaho where we get most of our Power from hydro. I think that we have saturated the Snake River with enough dams. Still the need for more Power is overwhelming the Grid. A coal fire was proposed less than two years ago and denyed. It sounds to me that we kinda need to perfect what we have while embracing all fields of Power generation. It amazes me how many people think hydro is green. LAWS OF PHYSICS you never get somethinig for nothing and it all impacts our enviorment unfortunatly. I personaly like the Idea of wind for Idaho. There is a desolate lava flow that streaches out for ever. Creaters of the moon to Boise. Yet, Im not sure it would be cost effective to get enough towers in and get it wired into the grid. Plus you have to compete with INEL ADVANCED MATERIAL WASTE SITES and testing labritorys. Water is definatly the way to go in some areas but not all.

We must always compromise: Yosemite valley would be a perfect place to store water, but I'm sure not going to be the one to suggest building a dam there! On the other hand there are still places (the proposed Auburn dam, put off for 40 years or so, comes to mind), where the loss of admittedly beautiful scenery would be compensated by the gain of energy (and storage for times of greater need), flood protection, new water sporting & fishing, and water supply (added beauty) for central and southern California.

The small stream hydro is fine for home use if you happen to have a stream running most or all year, but VERY few small hydro projects are going to have any significant storage, so during the part of the year when water is plentiful, most of it is going to pass by unused. As has been pointed out before in this series, the biggest problem with energy is storing it until it is needed.

Did you know that the first court battle the new Sierra Club fought was against the Spring Valley Water Company (and the City of San Francisco)? They tried to stop the damming of the Grand Canyon of the Tuolumne River in Yosemite National Park. They lost. The water from that reservoir supplies a large percentage of the SF Bay area's water needs plus much irrigation water in the nearby areas of the Central Valley. The electricity from the dam's generators lights up a number of cities in addition to all the street lights and trolley lines in SF. --John M.

First Up Masu, thanks for adding yet another excellent topic.

Any form of pico generation (hydro, wind, solar etc) only serves as an inspiration for others to act similarly. Having it grid tied is costly however of major benefit especially if it yields some sort of ROI.

Just last month I discussed this with a mate running an electricity distribution company in Australia who was telling me that during peak demand periods they shut off supply to the aluminum smelter plant in order to service the grid demand. So in essence, not only does Australia not have sufficient water, she also has insufficient generation.

We were toying with the idea of wind turbines mounted on top of high rise apartments and office buildings as a means to remind people to conserve. Funny but when I arrived back in Bangkok last week there was a new turbine mounted on a residential block in Ruam Rudee near Lumpini Park.

By and large we all take electricity and water supplies for granted and waste much of them.

In any discussion about hydro, one needs to take onboard the resultant benefits of water harnessing which injuncto, leads to short term environmental impacts and long term sustainability.

By and large it is the responsibility of governments to coerce power generating companies to offer a reasonable return for private co-generation. In this way, the "pico generators" have an easier means to an end as any investment with a reasonable ROI attracts the attention of other investors and institutions. Germany and California are excellent examples of this.

To give a rough outline of ROI I can say that our plans to build grid tied pico hydro plants (multiples of Vietnamese 50kW semi-kaplan units) in Bali have an ROI of 12 months. That's based on 20 hours per day of USD0.06/kWh and 4 hours of USD0.12. That's sufficient to have 20 units on order now (1 MW) which will be installed over the next 14 months. The investors are cautious but nevertheless committed. The environmental impact of these installations is zero save for the impacts of manufacture. On one site, the output waters side will service a fish hatchery so don't be surprised to find Barramundi 'Made in Bali' shortly. I'm not joking. Bali is 4 hours shorter flying time to Tokyo than the breeding grounds in Australia and at USD20 a kilo, well, the ROI just keeps getting better.

And then there's the CO2 credits. I haven't worked through these yet but at least in Indonesia this firm will buy tons of CO2 from us as well: www.ecosecurities.com

So in answer to the question, I would say "absolutely" and the rate of implementation is based on the rate of return.

Hi Tamu,

You may be interested to know that Origin Energy already have a co-generation scheme in place and will even subsidize the purchase of the plant and equipment. While this scheme is only aimed at solar power it is a huge step in the right direction. With a little bit of praise and some sucking up I would hope the scheme could be extended to include wind, micro-hydro etc.

As Tamu will tell you while Australians are tremendously inventive and love finding ways to pay less they are awfully conservative. Having an incentive as radical as co-generation being offered to the public in Sydney is a gigantic achievement.

We were toying with the idea of wind turbines mounted on top of high rise apartments and office buildings as a means to remind people to conserve. Funny but when I arrived back in Bangkok last week there was a new turbine mounted on a residential block in Ruam Rudee near Lumpini Park.

Directly on top of tall buildings may not be the best place for a wind turbine as there is usually a considerable amount of turbulence and this makes the engineering much more complex and less reliable. But as you said it is a great reminder that we need to be doing something and ever last little bit helps. Skyscrapers are very energy hungry items and can easily use all the power coming from a wind turbine.

The more I think about it the better this idea looks and with some forward planning large vertical axis wind turbines could easily be built into skyscrapers. Done properly it may even reduce the problem of increased wind velocity that can occur at the base of tall structures.

Whatever the solution it is going to require lateral thinking and some radical ideas not only on the part of the individual but by business large and small as well a government at a local, national and international levels. It's everybody's problem and everybody needs to work towards developing and implementing the multitude of solutions.

Masu,

Absolutely I agree with you that roof top mounted wind turbines are prone to turbulence and therefore not really practical above a certain rating unless prevailing wind conditions are acceptable. They certainly were in January in Sydney. http://www.bom.gov.au/cgi-bin/climate/cgi_bin_scripts/windrose_selector.cgi is an excellent idea of just what might be possible looking forward.

But as you rightly say, things like this provide all of us a constant reminder to conserve, consider and participate in the battle to save the environment and perhaps, the world as we know it.

I'm digressing from the subject matter of hydro here however I feel we're in way over our head with alternatives and hydro has always proven itself as the most cost effective method of generation but it's slow to construct as opposed to wind.

Not only do we need to immediately cease CO2 emissions, we need to set about a sustainable way to reverse the negative effects of the fossil fuel era. Branson and Gore are on the mark with the 25 million prize but what are the rest of us, those in the know, doing about this?

I only hope Tom Bearden & Co.'s MEG or Motionless Electromagnetic Generator becomes a reality sooner rather than later. Then we'd all be singing. http://www.cheniere.org/references/found%20phys%20letters/no%201%202001/p02.jpg

In my previous post I mentioned the systems semi-Kaplan systems for Bali. These units require a head of 6 meters and a flow of 1,600 litres per second. That's very manageable. Given a river or irrigation (Subak) system one may install these units in cascade fashion along the river course as the gradient decreases. With site works that runs out at about USD50,000 per unit. Being grid tied provides a means to an end with ROI (Investors). Here in Bali we can trade at USD 6 cents per kWh 20 hours a day and double that during peak times (4 hrs). Electricity is subsidized here and it costs them 14 cents to generate it. Needless to say there are endless negotiations going on to increase the price…but do the maths: it works.

Masu, the Vietnamese also manufacture smaller units like 1kW with low heads. Details at http://www.powerpal.com/products.html

To get an idea of what the big guys are doing, take a look at www.voithsiemens.com and especially look at this problem which is discussed in the September 2006 edition of HyPower magazine: "The hydro sector continues to face accusations that hydro power contributes to global warming. Cumulatively, the message is that freshwater reservoirs are part of the climate-change problem, rather than part of the solution, especially in warmer climates where the carbon cycle is more active." These guys are supplying the 3 rivers project in China with a stator so big you can house a symphony orchestra in the thing.

Omberdonk, you'll find references to tidal here: http://www.wavegen.com/pdf/Wavegen%20Brochure_may%2006_final.pdf

Has anyone here tried tidal? I mean it's technically hydro after all.

In short, whatever we can do to generate electricity by whatever means which does not harm the environment, we should. Large or small makes no difference. Grid tie makes sense (ROI). Scalar, God willing, will be the answer.

What sort of a world are we leaving/creating for our kids?

Good Day Gents,

I have enjoyed your postings daily & I have an uneducated thought & question upon water powered electricity, for you better minds.

Might A proper power system work well enough without an actual pond or stream ?

For example could one, if a large water tank were built say in a loft , Fill it to start with from the family water well, then drop that water into several smaller pipes down to create a higher pressure ( some what like a ram pump works ) , & then with a small amount of that power generated ( or a small water pump ) return that water to the tank , keeping everything going ?

Would there be enough electric power generated from 1 or 2 of those multi head hydro pumps I've seem advertised from so many catalogues , to power a homes basic or larger needs ?

Maybe enough to split hydrogen into fuel & then power said structures ?

Would a balance wheel add to the effect of the constant turning so as to not loose the Momentum or in case of water pump electric failure just ensure the return of water for driving the system ?

I have a large barn loft & have long wished to try this one on the family farm. No cows in the barn anymore, so no methane to digest. A ferrocement tank could be built for almost nothing .

What Generator to buy ?

Any suggestions on all this ?

Thanks & Cheers

bondjamesbond@rock.com

For example could one, if a large water tank were built say in a loft , Fill it to start with from the family water well, then drop that water into several smaller pipes down to create a higher pressure ( some what like a ram pump works ) , & then with a small amount of that power generated ( or a small water pump ) return that water to the tank , keeping everything going ?

It's a nice thought but unfortunately it will not work. The amount of energy (PE) stored in the water is proportional to its mass (m) the distance it has been raised (h) and the force of gravity (g) pulling it down, put mathematically

PE = mgh

No matter what you do or how you go about it you can only get back the same amount of energy that was expended lifting the water to the height it is stored at. In actuality you can only get a portion of the energy back that was use to lift the water as there are losses in both the pumping system that raised the water and the generator run by the falling water. If both stages were 80% efficient you could only ever recover 64% of the initial energy expenditure.

The reason hydroelectric systems work is that the sun has done all the lifting. Through evaporation and then precipitation the Sun has added the potential energy that is extracted as the water falls.

The whole concept is called the law of the conservation of energy and there is no way around it. No matter what you do you can only ever get back what you put in. If this were not the case then we wouldn't be having the problems we currently are with pollution and dwindling sources of fossil fuels.

If you still had cows you could burn the manure and steam it back up.

Hi

Province Québec in Canada mainly use hydroelectric power. Actually, there is only 3 or 4 power plant who are not hydro. We have installation of various size. From Micro power plant to the large scale installation of Grande Baleine at Hudson Bay.

In the last decade, there was a lot of micro power plant projects on smaller river. I don't remember of any of them was built. There was a lot of opposition from local population. Those I remember most are the project near the villages of St. Genevieve-de-Batiscan and Notre-Dame-de-Montauban.

Magog river linking the Memphremagog lake and St. François River at Sherbrooke as three mico power plant dating from the end of the 19th Century. They are single generators plant with dam installations.

We have the Beauharnois power plant who operates without dam. It's on the St Lawrence river, using the velocity of the rapids of Lachine. It's locate at the level of Montreal. That power plant is unique in the province for not using a dam. This one is also pre-war.

Small to medium size power plant are dating from 30s to 50s. Likes the St. Maurice River. Up to 6 dam and power plant are on that river. Three of them at the level of urban areas of Shawinigan to Trois-Rivières. However, the storage is the Reservoir Gouin that flood lot of area inhabited only by the very few Attikameks natives.

Finally, most of the very big installation who compares to the Hoover Dam are situated north of the inhabited region. Actually, only natives lives there. I'm talking about Manicouagan and James Bay. Most have been built in the 70s. Now, it takes from 5 to 10 years to prepare such project with all the contraints from environmental boards and natives demand. And we have the monopoly of a public company.

Right now, the fuzz in Quebec is on wind power generator projects. Since we don't have desert like in Arizona, the population will begin to complain when they will got the truth about the amount of forest destruction needed.

Another great thread Masu.

Not all energy that people use is in electrical or fuel form. I remember reading of a run of stream device which pumped water for household use without using external power. Simply put the device was a water wheel with a roll of poly pipe wound in a helix. Motion was allowed by a mechanical seal. On each revolution a slurp of water was picked up and the slugs of air between slurps were gradually pressurised forcing the water into the piping system. I can't remember the amount of head it pumped or even where it was installed ,although I think it was Victoria Australia. If I find it again I'll post it, by which time I'm sure someone will have found it or something similar. The beauty of the system was not needing a dam as in a hydraulic ram. Obviously the amount of energy tapped was small, but pumping water costs real money.

Sorry butting in again. Does anyone have info or links to any working tidal/ ocean wave/ ocean current power plants?

A new one, alway nice to have fresh idea's

http://cr4.globalspec.com/blogentry/985/Future-Energy-Sources-1-3-Energy-from-the-Ocean

succes

Hi omberdonk, welcome to CR4. You are probably not familiar with the this particular CR4 blog but we are one by one discussing any technology that could be used as a future ecologically friendly energy source. The Possible Technologies for Future Energy and Power Production is a list of the technologies that are seen as possible answers and has links to the discussions that have already taken place. If you can think of something that isn't on the list and you feel warrants inclusion please drop me an e-mail and I will happily include it.

Lots of great posts today - thank you all for contributing! Elnav, I think we should all like to hear more as you progress - please keep us posted. I think that the big hydro projects, like Niagra Falls, have their place if properly conceived and managed. The Niagra power station, by agreement with Canada, shares half of the water coming over the falls during the day with another power station on the Canadian side. During hours of darkness, when the tourist load is much smaller, they get to share three-quarters of the water. I haven't been to the Canadian power station, but the hydro facility on the American side uses quite a novel way of using the water they get - at night, they pump their share of the water up into a large reservoir built especially for that use. They use the base load of electricity that would otherwise be sitting on the grid at night. Then the next day when they need more electricity, the pumps are reversed and the water falling from the reservoir generates power, on it's way to the regular power facility. They generate electrict twice from the same water! This water falling from the reservoir complements the water taken from the river during the day and both flow through the lower power facility. I don't know what kind of environmental damage may have been done to construct the facility, but it seems like the facility is pretty sound and not very hard on the environment. Some of the other big projects, like Glen Canyon/Lake Powell in Arizona and especially the Columba River projects, have been hell on the environment. As for the small/homebrew hydro stations, they have their place as well. There are many such stations throughout the mountains in Colorado that serve to generate small amounts of electricity for their landowners. I would think that these systems are quite easy on the environment in most cases. My point is that the large mega-facilities can be good if more planning is put into the projects, while the small homebrew stations will have their part to do as well. I am a firm believer that no one method - hydro, wind, solar, etc. is going to solve our fossil-fuel dependance, but they will all have a part to do. So when Elnav speaks of a property with a hydro station, methane digesters and the like, I am excited that people can do it. The cost is the killer right now, but I am convinced that when economies of scale finally kick in, small hydro stations are going to be really cheap to install and maintain.

Sleddriver wrote:regarding the Niagra power station, the American side pump their share of the water up into a large reservoir built especially for that use. >> snip<< I don't know what kind of environmental damage may have been done to construct the facility, but it seems like the facility is pretty sound and not very hard on the environment.

REPLY:: I seem to recall that the Niagara pumped storage resevoir began as a depleted quarry and was expanded to suit.

Concerning my own project, the property was not suitable. Stream flow too little and mostly seasonal for three - four months. So much for real estate ads!! I'm still looking.

I recall seeing a TV show about a New England wood shop that was powered by a water wheel. The power demand from the furniture factory was too great for the available distribution lines. Owner decided to resurrect and rebuild an old water wheel already on property but abandoned for decades. A similar situation was implemented somewhere in Bruce County in Ontario near Wiarton from what I was told.

Ontario abandoned many older small power dams as being uneconomical for the technology of the day ( fifty years ago)

Instead Ontario bet the whole pot on nuclear power. Well now we know better. I was actually accepted for the first group of trainees to become nuclear power station operators. In restrospect, I'm now glad I chose another career option. Much later I worked in a power utility where we hired a lot of station operators who had previously been working in nuclear stations like Pickering. Hearing their job war stories simply confirmed the wisdom of my early career choice.

Many of these abandoned hydro power generation sites still have ample water flow to drive micro generators using the latest technology. Some of them may even work without any dams whatsoever by using newer generator designs.

The New York -Erie barge canal still powers many of their locks stations with local generators dating back 100 years. These are not grid tied, but stand alone point of use.

regards,

Elnav

Before we get too carried away with damming small rivers consider the following:

A sobering fact is that in the US and several other developed countries, a greater number of dams have been de-commissioned and removed or bypassed than have been constructed over the last decade. Most of these dams have been "small" ones whose electrical contribution became such a small percentage of the local generating capacity that it was deemed more practical to do away with them and return the river to some semblance of its former state.

A direct quote from the article: "Down Go The Dams", Scientific American, March, 2007 issue:

"Some 800,000 dams exist around the world, but small ones -and even some larger ones - are increasingly being removed so rivers and streams can recover."

This is not to say they won't have a place, rather that it is not likely to be a big one in the future.

Also I'm reasonably sure that these stats don't include microturbines of a few kW or so.

Greg

Greg G, I don't want to appear as though I advocate damming the small rivers and creeks - just the opposite. The microhydro projects I mean are of such small capacity that they only use a small tube/pipe (two to six inches or so) to draw water from the stream or river, then return it to the source. These microhydros aren't going supply a city or even a neighborhood, but when planned well they can supply a home or two. This hopefully relieves a homeowner or utility company from having to run a power line through an area otherwise not supplied with electricity - big expense, possible environmental damage, etc. We have more than a few of these up in the nearby mountains and they don't appear to be doing much damage to the environment.

PE = mgh

No matter what you do or how you go about it you can only get back the same amount of energy that was expended lifting the water to the height it is stored at.

Ok "Mas", I understand the standard classroom answer & I remember it from dear old, bloody old - school, but those of us stranded in the fields have to make due with what we have.

I remember a job when we once needed several hundred gallons of water to fill some 55 gal drums. There was no supply line but a creek & pond were near by, so I put a 5/8" garden water hose in the stream bed & filled it with water. Then while someone else held 1 end down low in the still water pond, I put my finger over the other end (hose still full of water) & walked quickly up - fifty feet or so, to the drums & let my finger off the hose end, to find water streaming out my end.

This continued untill all drums were filled & it didn't take too long.

No Pump-Just the water in the hose from a pond of basicly still water. If I understand PE = mgh this should not have worked, but it did & it has worked for me since when I needed to move water, but had no pressurized supply lines.

OK, So why would this simple system not also work & return our water, if enough hoses were fixed in place to keep our tank filled, without expending any of our power generated ? Perhaps this is just a conversion of the energy to the hose pipe but effective.

Additionally, might not a conversion of power to a higher level than from a hydro power generator drive an Electrolysis water splitter and might it not help this systems expansion of power levels. Counting the losses, would not the hydrogen gas produced, be of a greater energy sum than the 1st hydropower generated from a water supply? I remember that the flammability of hydrogen was much greater than just gasoline about 4 to 75 percent compared to 1 - 7 for gas. This same property, however, makes hydrogen hazardous to handle though very hot burning.

It seem to my simple mind, that if a controled cascading effect can be started, then the end of that effect can be postponed , to create greater total outputs through such conversions.

Thanks & Cheers.

bondjamesbond@rock.com

"If history has taught us anything , then anything is possible". Michael Corleone

Sleddriver back in post #14 talked of,

"They use the base load of electricity that would otherwise be sitting on the grid at night. Then the next day when they need more electricity, the pumps are reversed and the water falling from the reservoir generates power, on it's way to the regular power facility."

The Snowy Mountains Project in Australia has been doing something like this since the 1960s. The entire scheme required several pumping stations to lift the eastward flowing water to a sufficient elevation for it to flow towards the west rather than is natural easterly course. Initially the electricity for the pumping was supplied by hydroelectric power stations that were part of the system. They soon realized however that they could turn the whole pumping and generation into a bigger money spinner by buying surplus power at a greatly discounted price for use in pumping. The water was then held in the elevated reservoirs and used for generating power as it flowed back down in a westerly direction during periods of peak load. The price they were selling the generated power was something like 10 times the price they were paying.

James Bond in post #16 had the following question

I understand the standard classroom answer & I remember it from dear old, bloody old - school, but those of us stranded in the fields have to make due with what we have.

There was no supply line but a creek & pond were near by, so I put a 5/8" garden water hose in the stream bed & filled it with water. Then while someone else held 1 end down low in the still water pond, I put my finger over the other end (hose still full of water) & walked quickly up - fifty feet or so, to the drums & let my finger off the hose end, to find water streaming out my end.

You seem to contradicting yourself, either that or I am getting confused. You said

"I put a 5/8" garden water hose in the stream bed"

but then qualified this with

"while someone else held 1 end down low in the still water pond".

OK then where was the water flowing from and to? If the water was flowing from a moving stream to the elevated tank then there is nothing extraordinary here. All you are doing is converting the kinetic energy that the moving water possesses to potential energy. Given the following

PE = mgh & KE = ½ mv² therefore

mgh = ½ mv²

h = ½ (mv²) / (mg)

h = ½ v² / g

This means if the water was flowing at 1 ms^-1 we could raise if 50 mm, and for the 15 meters you are claiming about 17 ms^-1. That's about 38 mph so I suspect I havn't got the whole picture.

If you can give me some more details then I am absolutely certain it will reveal that we are not getting something for nothing.

He is talking about using a siphon. It works fine as long as the absolute height at the delivery end is lower than the absolute height at the source end. I have used it many times to siphon beer and wine from their fermenter into bottles. Not that I have done it but, I have even heard that it can be used to "borrow" gasoline from the tanks of parked vehicles late at night....

Hi Guest,

I was giving Mr. Bond the benefit of the doubt and assumed that he knew how a siphon worked. Having said that I have a question for you about siphoning,

How high a barrier can you siphon a liquid over and what factors effect this height?

I will give you the answers in 24 hours if nobody has given it before.

My guess is about 23 feet above the water head.

The temp of the water is one critical aspect as well as the dissolved minerals/ chemicals in it. The other big facter is the velocity of the water as it goes thru the siphon hose.

Above this the water will "pull a vacuum" and the siphon will stop.

Guest was about right, except that the principal factors are the atmospheric pressure and the density of the water (which of course means temperature).

Back when we weren't so concerned about liability I used to illustrate this by having students see how far they could suck mercury up a glass tube - most could only do about 8 inches of the theoretical 29 or 30 inches.

I suspect that Bond's original tank filling was an optical illusion: the terrain made it appear that the barrels were higher than the input point, when in fact they had to be lower. If he filled them quickly, they had to be significantly lower. I just used siphoning last night - bottling some home-made wine!

Theoretically there is no height limit over which you can siphon.

Lets say you were on a hill (Lets say 50M high) and you had a Large Tank next to you on one side and a large wall (Say 1Km high) on the other. Behind the wall is another large partly filled tank at sea-level.

If you could Fill a hose (Un-crushable) 2070 m long with water and seal both ends, pass one end over the wall and have both ends submerged before you removed the seals at each end, the water would happily flow over the wall into the lower tank.

There are a lot of other factors that may have an effect here such as friction of the water on the walls of the hose, cavitation, the weight of the head which could cause an "airlock" by pulling gases out of solution.

Now if you had to suck the water over the wall using your mouth.................

NOT true! The only thing pushing up on the water is atmospheric pressure. Suppose you filled your long hose or pipe with water (on roughly level ground) and close the far end. Then you start to lift it, keeping one end closed and the other end under the surface of water in the higher tank. As you lift it, the weight of the water will make it try to flow downhill, reducing the pressure at the high point, whether that is the opposite end or some point along the length of the hose. As soon as that point is around 23-25 feet above the surface of the water in the tank, the pressure in the hose will get so low that the water will boil. (Water boils whenever the pressure pushing on the water is less than the vapor pressure at that temperature - connect any good vacuum pump to a strong clear container of room-temperature water, and you will soon see water boiling at room temperature) As you continue to lift your hose higher, more of the water will boil, filling the high part of the hose with water vapor, and allowing more of the liquid water to flow out the entrance to the hose.

If you sealed both ends of your hose before you lifted it, you could get a full hose over the 1km wall, but you would have roughly 1600 psi (11MPa) at the bottom of the hose. You better use a tool, not your hands, to unscrew the hose cap! When the cap is removed the water will come out with considerable force. The same thing will happen at the upper end, with only a little over 1500 psi (less due to your 50m altitude). That is the water will come out of the hose into the higher tank.

Try it: Fill a 50ft or longer hose with water, close one end, and clamp the other end under the surface of the water in a small (like a half gallon) container half-full of water. Pass a rope over a pulley on a 3rd floor or higher balcony, and use the rope to lift the closed end of the hose. As soon as the water in the upper end of the hose is below the vapor pressure of water at that temperature, it will start to boil, and any further lifting will cause more boiling, forcing water to flow out of the hose, raising the level of the water in the container.

I take your point about the water boiling. In fact I made mention of gases coming out of solution due to the head.

For the sake of this theoretical argument, let us make the liquid hydraulic fluid.

Also note That I was talking about having both ends submerged before decapping.

Finally, I wasnt talking about removing the caps by hand as in this argument I have the luxury of being able to use magic (along with un-crushable hose)

Johnoz,

You are still wrong.

And, since hydraulic fluid is less dense than water (about .9), all that means is the maximum limit would be proportionally higher than with water, meaning a theoretical limit of about 11.5 meters instead of 10.33.

Using mercury instead of hydraulic fluid and the maximum rise drops down to only .76 meters!

Your error is in assuming that the weight of the liquid on the down side will "pull" the liquid up the other side. It does not work that way, any more than a pump of ANY kind could pull it up higher than atmospheric pressure would support it. Unless of course you use magic for that too.

Greg

I don't know if you have ever seen a television series called "Connections" which is written and presented by James Bourke. Each episode is a very interesting meander through history where one idea leads into the next with some sort of common theme. It's not too dissimilar to the way a CR4 discussion goes from one topic to something completely different in the end. They are all repeats but if you ever notice them they are worth watching.

Anyway I was watching an episode earlier today called "Something from Nothing" and he was waffling on about how the pope stated that there was no such thing as a vacuum and that the empty space at the top of a column of mercury was a protestant conspiracy. The refusal to accept that there was indeed a vacuum held up science for a considerable period and it wasn't until the concept was accepted that they could engineer a workable solution to the flooding of mines. It's incredible how people can get hung up on a concept and how that can halt progress in what would seem to be totally unrelated fields.

Good points, as usual, Masu!

Gosh, it must have been fifteen years ago that I watched 'Connections' and 'The Hitchikers Guide to the Galaxy' on PBS - I'll have to check my listings (I rarely turn the TV on any more, since I get my news on the internet), to see if they are repeating them here in the USA.

Dick

I'm not sure but I think he ended up doing 3 or 4 series in the end. The current repeats are "Connections²" but even though it's about a decade old it's still relevant and shows same classic examples of where people's blind faith has stopped them from seeing what we see as blindingly obvious.

About a year ago I watched a program about a group that were trying to read a manuscript of Archimedes. Apparently some time during the so aptly named dark ages a scribe thought Archimedes work was worthless so he washed the paper and use it as a prayer book, of something.

With modern technology they have be able to retrieve most of the original manuscript and found something that could have changed history in unimaginable ways. It turns out that Archimedes was working with the concept of dividing a continuously varying function up into a infinite number of infinitely small sections. Put simply he had come up with the basic concept of calculus some 1,500 years before Newton. In one foul swoop the monk with his prayer book probably put the world back a thousand years.

It's impossible to know but the lack of a tool like calculus held up science for a long time and the mind boggles at what we may have achieved by now if we had calculus a thousand years earlier.

My take on hydroplants are that they are a great environmental disaster. Not only does it ruin the natural streams it also have a great many serious impacts on nature and global climate.

In the stale water in front of the dam organica and inorganic materials sink down. The organic materials rot and creates metan gas and other toxic gasses in the process that are potent green house gasses.

The inorganic materials will no longer fertilise river banks and eventually the sea which reduces the fertility and in turn lead to less CO2 uptake. The loss of agricultural potential and fishing is also a major concern.

Does anyone have a supplier for a hydro pump/generator of about 1000 watt size?

Water head per foot height is equal 0.433 psid. Ten foot water height is 4.33 psid. One hundred ft ehad is 43.3 psid. A hydro pump/generator will pump water into the tank when power is available (ie grid power, wind generator or solar generator). When the wind is silent and the sun shaded, the hydro generator is used to generate power. Large utilities like TVA's Raccoon Mountain hydro pump generators operate at roughly 90% efficiency both pumping and generating. Design is for 100 ft head and greater.

Qestion is where can we purchase a small 1000 watt hydro pump/generator preferably for low head high flow?

The ambient pressure is the limit for a siphon to function. Theoratical Sea level at 14.696 psia with 0.433 psia per foot equals 33.94 ft maximum head for a siphon to function. The force of atmospheric pressure will push water to a height of 33.94 ft. If the water tank, however, is closed and pressurized ie with solar heat or a pneumatic wind pump, the siphon can be fully functional to a height equal the pressure in the tank.

You may need to do a fair bit of design work yourself, but emerging technology is all on your side. Two websites worth a good look are International Rectifier and ABB look specifically for "Permanent Magnet Synchronous Motors". The design of your pump is critical right down to the diameter of the impeller which needs to matched to motor for best possible efficiency. Pipework will also need close attention to not eat your energy. How you intend to use the power regenerated will guide the electrics. Generating Authority scale projects have accurate governors to maintain frequency and this approach is possible but will likely have a lower end cut off point. The other option is inverters, but every extra conversion results in efficiency loss. If the energy is coming from renewables this may be acceptable rather than lose the energy through lack of storage.

Hi Cornstoves, You asked;

Does anyone have a supplier for a hydro pump/generator of about 1000 watt size?

I remembered somebody referring to a company in that manufactured small hydroelectric generator systems in a discussion some time back. They referred to an Indian company called Jyoti. The smallest they make is a 5 Kw unit but according to their web site they can operate with a little as 2 m head. I have never had any dealings with this company so I have no idea if they are a reputable or not but the photos on their web site show what appears to be a fairly good quality product.

I can't hurt to ask and if you do end up dealing with them I would be interested in the ultimate outcome.

Home Power magazine (http://homepower.com) usually has some advertisers that sell small hydro equipment, you might try there.

Ok here is the answer to the siphoning question.

The primary factors that effect the height that a fluid can be siphoned are the density of the fluid, the atmospheric pressure and the force of gravity. These are in turn effected by the temperature, altitude and location.

The theory behind this is that the fluid being siphoned is not being sucked up the pipe but rather being pushed by the atmosphere. Since the atmospheric pressure is a finite figure then the height that the fluid can be pushed up is also finite.

Lets look at what happens with the water in a pipe and how these factors are related. The force pushing down on a column of fluid is proportional to the mass of the fluid in a column multiplied by gravity and we can calculate the mass by multiplying the density of the fluid with the volume of the fluid therefore

Fluid_Volume = Column_Area x Column_Height ……Equation 1

Fluid_Mass = Fluid_Volume x Fluid_Density ………..…Equation 2

Fluid_Force = FluidMass x g …………………......…Equation 3

We can therefore say that the pressure at the bottom of the column is the force generated by the mass of fluid in that column divided by the cross sectional area of the column therefore

Fluid_Pressure = Fluid_Force ÷ Column_Area ………Equation 4

So by substituting we can now calculate the pressure at the bottom of the column as follows

Substituting Equation 1 into 4 gives

Fluid_Pressure = FluidMass x g ÷ Column_Area

Substituting Equation 2 now gives us

Fluid_Pressure = Fluid_Volume x Fluid_Density x g ÷ Column_Area

Sigistuting Equation 3 then gives us

Fluid_Pressure = Column_Area x Column_Height x Fluid_Density x g ÷ Column_Area

Cancelling the area and tidying give us the final answer to the pressure

Fluid_Pressure = Column_Height x Fluid_Density x g

Note that the cross sectional area of the pipe has cancelled out, which means that the diameter of the pipe will have no effect on the height. Now for the fluid to be forced up by the atmosphere the pressure caused by the weight of the column can be no greater than the atmospheric pressure pushing the water up, therefore

Atmospheric_Pressure ≥ Fluid_Pressure

Atmospheric_Pressure ≥ Column_Height x Fluid_Density x g

Column_Height ≤ Atmospheric_Pressure ÷ (Fluid_Density x g)

So lets now look at the maximum height for water. For a standard atmosphere the barometric pressure is around 1,000 Hpa or 100,000 Nm^-3, water has a density of roughly 1,000 Kgm^-3 and the acceleration due to gravity is about 9.81 ms^-2 so substituting these figures give us

Column_Height ≤ 100,000 pa ÷ (1,000 kgm^-3 x 9.81ms^-2)

Column_Height ≤ 10.19 m

So there you have it, the maximum height you can siphon water over is around 10 m (32 feet) and the primary factor that effect this are the atmospheric pressure.

Hi Masu,

I liked your clear illustration of the answer showing the actual derivation.

Taking the "lazier" approach, since water "head" is so commonly used to represent pressure, I simply use the conversion (at sea level):

1 atm = 14.696 psia = 406.782 inH₂O = 33.899 ft of water head

Or, 1 atm = 10.332 meters of water head

(As a side note: 1 atm = 1.01325 bar = 101,325 Pa)

This represents the maximum height of a column of water that can be supported by atmospheric pressure.

In practice, with flowing water and the consequent energy losses, even a 9 meter rise would be excellent for a siphon or pump suction lift.

For a historical perspective:

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

Greg

Hydroelectric power is a local solution.

It can't be used all over the world. Typical, most of the people live in low and /or flat areas, mostly near the sea.

Transforming the potential energy in water as it runs down is limited.

If you have the local possibility, go and use it. In mountain area's this market has it's known supplier base. With scales going from pico to mega.

It is a pity to see the state most ancient water mills are: but as stated earlier: they would only give some kW and that is not worth the effort. It is this mentality that needs to be countered.

The big problem with water and height is the energy that is contained in it. When I want to have the energy stored of 1 liter of diesel (40.9 Mj) I need to have a potential difference of 4.17M kg*m

If the height difference would be 1m you will need 4169 ton of water.

With 1000m of difference you "only" need 4169 liter

Here you have the main problem of hydroelectricity: scale.

Hello All, and Hello Mas,

Ok ,I remembered 34 ft as the height ability to siphon by way my local well digger a few years ago, but I'm confident your knowledge of engineering is correct at 32 ft & thanks very much for the benefit of your doubts & your knowledge.

I must say the idea of using the power that's generated when its not being demanded & then storing it up for later use for the water redelivery to the tank did not even occur to me. Good Thinking !

I must look into this further as I think the path could be this way.

As Gwen noted Hydro is for local users ( that have the ability to do so ) & that's why I would like to see if the water tank generator idea I proposed earlier has any chance.

We have water on several of our farms, but we would have to build ponds & a dam spillway & then re-enter that water back to the stream. Living now in the USA, we have a lot of interference from our environmental protection agency & messing around with the waterway for a small project, is just about too expensive to consider, Hence - the water tank generator idea.

Ok Masu, & everyone else too, I'm certainly known for being better at destruction than construction, so show me the way this water tank pond generator COULD work; because this makes hydro available to everyone, not just those with a stream & a dam.

Thanks & Cheers. James

bondjamesbond@rock.com

If you have a reasonably large tank, one possibility would be to use wind to pump water into the tank, and let the water flowing out of the tank generate electricity. If you have a wind that tends to come up at intervals (mine tends to blow up into the mountains in the afternoons), the water could give a steadier flow of electricity. I have made no calculations to compare using water as a storage medium to just generating electricity with the wind and storing it in a battery...

It all comes down on the size and scale:

How much energy do you want to have stored?

What height difference do you have? (don't try this when you are in flatland)

The problem with hydroelectric generation is the regulation, you want a constant 120V 60Hz cycle to drive your appliances.

A solution would be to couple the windmill direct to a pump that will move water from the flow to the storage. in case you need energy you ask the water back though a turbine. After all it becomes very complex. If you would use the power for illumination of the barns, it can be handy and worth wile. (a timer on the turbine and your light is on when you want)

A decent inventory of power usages, coupled to the fuel you use can learn you where you can use hydro / wind / solar energy and where you will stick with the grid and petrol driven vehicles.

eg: ice cold water to cool down milk, you can use wind to drive a cooling compressor and store the cold in ice. (get rid of the electric drive of the compressor)

Gwen

Ok lets have a look at the physics behind storing energy using a water tank.

First of all electric motors and pumps are not 100% efficient so you are going to loose a certain amount of energy pumping the water up into the. Then when it falls back down and generates electricity you will loose even more. A good starting point is to assume that you will loose about 20% at each stage therefore your overall efficiency will be

Efficiency_Overall = Efficiency_Pump x Efficiency_Generator

Efficiency_Overall = 80% x 80% = 64%

Now potential energy is mass times height times gravity and ore overall efficiency is known therefore

Energy_Stored = Efficiency_Overall x mass x height x gravity

Energy_Stored = 64% x 1Kg x 1 m x 9.81 ms-2 = 6.2784 j

This means that for every liter of water that we pump up we can effectively retrieve about 6 joules of energy for every metre it is above the generator/pump system.

This is probably meaningless so lets look at how much water we would need to pump up to a tank that is 15 m (50 feet) above the ground to get back a kilowatt hour.

1 KwH = 3,600 s x 1,000 w = 3.6 Mj

Water_Volume = 3.6 Mj / (6 l x 15 m) = 40 Kl

That means we are going to need to pump about 40 tonnes (10,568 US gallons) of water up to the top of the tower and expend about 1.7 KwH or electricity to get 1 KwH back from it when it falls back down.

That's a fair amount of water to try and store so I would suggest that trying to store energy with water in a tank is probably not a viable solution. For it to be a feasible you would need something along the lines of a small lake or reservoir.

Oh Come On Masu, Tell Us What You Really Think About It

Here in Pettycoat Junction 10,000 Gallons is just an average sized kiddy pool from Walmart. Hell, we have 3 .

50 feet tall, well telephone poles are a dollar a foot at the local power company (Used) but still pretty good for platform construction & one can buy some over-kill strength at that price; I allready have a year round deer stand taller than that you could live in .

Now, your moving a lot of water per minute, yes. ( 176.13 Gal ) & storing a great deal too.

Do you really have to store so much ?

& do you have to be so high with iy to get enough force ?

I'm no expert , just asking a few questions of you college boys and the 1.7 KW expense for 1 KW of gain is a real problem, if a way to fix that is not available.

This All "Kinda Minds Me" of the 2 local boys paying a $1 for mellons & hauling them North of the Mason/Dixon Line (scarry up there) & "sellin" them for a $1. They sooner figured out, they wern't making "nothin", so - they had to buy a bigger truck "n" haul more mellons to make um some real money.

Hopefully, someone will show us they ARE as smart as we all HOPE they are

and look at this with a fresher eye , perhaps even without a fixed perspective of how this must be ; and they might see a way around the over expense of power you calculated & hydro is then a real wide spread possibility.

See yall in the watermellon patch; I'll be out back watching the bucks'um girls take a bath in the big ol waterin tank - Junction , Pettycoat Junction =+=+=+=+

Cheers all , James

bondjamesbond@rock.com

Do you really have to store so much ?

& do you have to be so high with iy to get enough force ?

You either need the height or the mass. Decreasing the head height means an increase in mass and vice versa. There is no way round it that's the way the physics works.

Is building a 40 tonne water tank at the top of a telephone pole with a pump and generator worth the 10-20 cents of electricity it can store?

Well that's up to you. I'm not sure but I think it would be cheaper to use NiCd batteries but I have been wrong in the past.

Well Mas, not on A telephone pole at least.

Someday Hopefully, someone will show us THEY ARE as smart, as we all HOPE they are ...

& yes make sure the physics work too .

"I am enough of an artist to draw freely upon my imagination.
Imagination is more important than knowledge.
Knowledge is limited. Imagination encircles the world."
-- Albert Einstein

wasn't he not a just a clerk, in a patent office

Cheers, James

bondjamesbond@rock.com

Einstein was a clerk in a patient office only as a job to help put him through university.

The point I was trying to make is that for storing energy you need huge amounts of water and reasonable height variations. In a domestic situation it's not really practical but if you are talking about lakes and dams then that is a completely different matter.

If you wish to store energy with water you are better heating the water. With the height you get 9.81 joules per liter per meter where as by heating it you get 4,187 joules per liter per degree Celsius.

I Agree.

& Then On To How.

Thanks Masu You Have Good Ideas.

Cheers, James

Bondjamesbond@rock.com

Dear Masu,

It is only recently that I have found this blog , and have noted your Sydney domicile. If this is not intruding on you I would appreciate a conversation with you . My mobile number is :0405-846-662. Thank you in anticipation . Best Regards,

Labor Omnia Vincit

Hi Labor,

If you follow this link to CR4 internal mail system you can send me a confidential message containing your email address I an sure we can work out a way to converse directly.

It's not a good idea to publicize personal details like phone numbers or email address on an open public forum like this but the internal CR4 mail system is far more secure and safe enough for things like this.