Using river flow to pump water uphill (for later power generation)

[kipcole9]

I have a house in a semi-rural location with river frontage.  Its a large river (Hawkesbury River, near Sydney Australia).  The river is tidal at this location.  I am looking for install a co-generation or battery charging capability. We are self sufficient for water and composting for waste.  Now to solve the power problem.

The property orientation (westerly) and siting (against a 100m steep bluff) means that neither solar nor wind power will work.  I do have an inverter and batteries installed for backup to the mains system.  The inverter has a solar panel input.

Is it possible and practical to use the flow of the river to pump water to a storage facility and then use gravity feed to run an alternator or turbine (depending on whether co-gen or charging)?

Is it technically possible to use river flow to achieve the same result (there is basically no drop as the river passes my house)?

I'm looking for any advice, pointers, references, books or anything to educate myself and formulate a plan.

Thanks for any help - many hours of googling hasn't helped thus far.

--Kip

[Airstream]

With any direct sun at all Solar is still possible, just need to double or triple up on panel count. Ya, I know, no help at all.

This be dreaming, but Tidal could be used depending on the peak/ebb heights and any room you have to impound water, or even wave action can yield a little power.

http://www.nooutage.com/  has some neat online tools you can plug in height, flow, etc to get possible outputs...

[Yyrkoon]

Yes, it has been done. Try searching the internet for 'Sacramento California irrigation methods'. I am pretty sure it requires siphoning.

[thirteen]

possible chance for a ram pump usage of some type/ Just an idea

[dnix71]

If the river flows well, why not tether a water wheel on a floating platform with a cut out in the center for the sumerged part of the wheel. Pumping it 300 feet straight up for later use will require a pretty decent pump. At least you don't have to worry about flooding with a drop off like that.

It might be more efficient to just run a generator off it and send it to batteries. Electrons are much easier to lift.

[MattM]

Isn't the siphon limit for elevation around 10 meters?  This is why deeper wells use lifting.

[Yyrkoon]

I do not know the technicalities of siphoning personally, but an old boss of mine worked for the city of Sacramento for a while as one of their engineers. He explained to me what he did, but its been years since hes told me, and I have probably forgotten a lot. Siphoning is what I am remembering . . . coupled with some sort of strange 'lock' system similar to the panama canal.

Maybe I should have just kept my mouth shut ? heh.

[laskey]

Yes, I believe you could use a ram pump if you have a fairly constant flow.  You need to have a conical intake capturing a wide entrance area, then it has to narrow over a distance to a smaller diameter pipe. Then you need to have the pipe curve logarithmically to near vertical.  Your ability to raise water a distance relies on the speed of the river flow, the size of the cross-section of the intake, and its ratio to the size of the final pipe's cross-section.  That smooth curve is very important to minimize resistance in the pipe.  My suggestion is to never shut it off if you get it running.  Just let the overflow fall back into the river,  People love a waterfall.

[kipcole9]

Some interesting suggestions and ideas, thanks.  The idea of using river flow to push water uphill so that it can be stored to turn a generator on the way down in on the assumption that the river flow is too low for direct generation.  

However I did come across an experimental underwater turbine at http://www.electricmotors.machinedesign.com/ArticleDraw.aspx?artid=57268 which looks very interesting.  Bi-directional so tidal direction doesn't matter, directly generates (as one of you said - pushing electrons should be easier than water).

I could probably mount this thing on the underside of my boat pontoon so limited saftey issues and no impact on the riverbed.

The tidal flow is only about 1m and I haven't measured the river flow (hmm, there must be a fun toy that can do that).

Does the accumulated wisdom here think direct generation is a scenario worth pursuing?

Cheers, --Kip

[zeusmorg]

 You could use a undershot waterwheel, and if it's a river with a strong flow, the torque would be available for gearing up to a higher speed to run a generator. there are losses in a gearing up setup but not as great as lifting the water 300'!

Usually water is lifted to a greater height for either flow irrigation, storage for higher pressure, or as a "battery" of energy for later generation. Some hydroelectric systems use their off peak power to pump water up to a reservoir for later use during high peak demands. Just think of it as a large battery ..

 The equipment involved in piping both up and down has to be factored into the costs,and the overall power losses you'd incur would be FAR in excess of other losses from a waterwheel mounted genny and a good storage battery setup. and the latter would be cheaper, in my estimation.

 I've built an undershot wheel on a dock attached to a genset that does quite a nice job. I used automotive timing belts and pulleys for the gearing. works fine in a wet situation.

[electrak]

In Maine They are propossing a plan to dig some tunnels some 2000 feet deep to do just that, let water flow down for peak power, then pump it back out at night/low demand, or when the wind is blowing.

[Seedler]

Kip,

This is an interesting site that explains how to make a basic ram pump.

http://www.clemson.edu/irrig/Equip/ram.htm

I'm sure you could upscale it.  I have played about with an old cast iron ram pump in the past.  I found that the pressure of the water was not that important.  A long straight inlet pipe with a small fall worked better for me.  I only had a fall of about 1/2 a foot over about 7 or 8 metres.

Dee.

[spinningmagnets]

When you say "tidal" do you mean that you are near enough to the ocean that when the ocean tide is coming in, the river flow comes to a stop? Then as the tide goes out flow returns?

Before grid electricity became widespread and fairly cheap, I have seen pics of water wheels that used a gear-up to spin an alternator for local power. Perhaps inefficient and not cost-effective if you have to have someone build and install it, but...

When the Romans were under seige and couldn't reach their grain mills to make flour, they put water wheels on barges anchored in a river, worked OK.

If you have a lot of energy and near-free junk, it shouldn't be too expensive to cobble one together to get a few Watts. Might I suggest you take a glance at a "Poncelet" wheel, and compare it to other options? The curved scoops and enclosed sides reduce turbulence and increase energy capture compared to the easier to build flat-paddle wheels (or so I'm told)

http://www.waterwheelfactory.com/history.htm

If you had access to a lot of Roman-trained European slaves, I'd recommend that you Google "noria", but most European slaves these days couldn't build a noria, aqueduct, and hillside gravity-irrigation reservoir if their lives depended on it...

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

[scottsAI]

Kipcole9,

Any chance you can put wind turbine or solar on top of bluff?

100m is no big deal for wires.

Have fun,

Scott.

[zeusmorg]

 The main problem in this situation is you need a drop from your source of water to the ram, usually best at a 1 to 4 fall. Since rivers are usually the low point, you'd need some other way to pump the water, like an undershot waterwheel, with pumps attached.

 A ram pump won't work without sufficient drop and a way to drain off the excess water.

[thefinis]

http://www.wildwaterpower.com/

Some old but still workable ideas for pumping river water. I think you should look at some past threads on storing water for power production. You are probably better off trying to charge batteries with a slow rotating water wheel rather than trying to use water for power storage. The efficiency losses of this type system will eat most of the power from the original river energy capture.

Finis

[Bushwhacker]

While I realize this is not the answer you are looking for, take a look at Hydraulic Mining. They have a similar problem and got a solution. The amount of lift you seek is the biggest stumbling block.

http://www.google.ca/search?client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&channel=s&am
p;hl=en&q=hydraulic+mining&meta=&btnG=Google+Search

Cheers!

BW

[Bushwhacker]

Just to expand on this topic, have you thought of the concept of something like a turbo charger? A large impeller in the river driving a smaller impeller/pump to force the water up hill. I'm not an expert on the topic by far but just pitching concepts here.

Good luck!

BW

[scorman]

check out this thread:

http://www.greenpowertalk.org/showthread.php?t=474

this will only work if the height you need to pump up to for storage is not too great

Stew Corman from sunny Endicott

[richhagen]

Yes, you only have atmospheric pressure to work with.  When the force of gravity acting on the water exceeds that required to create a vacuum in you pipe, siphoning will not work.  This is about 33.9 feet or 10.3 meters at sea level.  Rich

[kipcole9]

Thanks everybody for the pointers and suggestions.  Lots to digest and consider.

I am looking at whether I can do solar/wind on top of the bluff behind me.  I know technically thats easier - but I suspect that planning permission may be a little challenging :-)

The river is tidal - I get about 1m rise/fall.  I'm about 15kms from the sea - the tidal effect can be measured at least another 60kms farther up.  So I guess that means that I have bi-directional flow.  Faster flowing when the tide is going out; slow flowing when the tide is coming in.  I mean, since I have a tidal effect, the flow must by definition reverse, no?

I really appreciate all the thoughts and ideas.  I'll report back when I make some progress.

Cheers, --Kip

[TomW]

Kip;

Have you considered a floating weight that you let the tidal rise lift a a pontoon or something, then use that weight to drive a generator / alternator?

similar to how some docks ride up and down on poles with rings around them to keep it in place over various water levels?

Could even "disguise" it as a common dock? Might be less hassle to do as you only use power of the elevating water not flow. Seems you could extract energy both rising and falling and 2X every day?

Just an idea I didn't follow thru on too far as to "how".

Should be easy to calculate the amount of energy in X pounds lowering Y feet in Z time, too.

Tom

[MattM]

A tidal flow is not usually reversed flow.  Not to say it cannot be, but that is the exception.  It can be in something like a channel through a sound, where there is a structured flow cutting below the top water like a rip tide.  I suspect your general water flow rate is lessened in the high tide as the water doesn't have as much potential energy; its less elevation at that point relative to the sea/ocean.  You probably have a little reverse flow along the top of the water as high tide moves in, but it should be negligible.  The more troublesome issue would be turbulence in the flow as the water backs up during high tide.  It is harder to extract energy from a turbulent flow.

It may just end up being entirely not worth your while to use the current's energy during high tide's ebb if you cannot reach the structured flow (the channel?) since the overall water flow is slower.  You will still have flow somewhere in the river.  Its more than likely that flow is out there in the channel rather than on the surface.

[riverpower]

Hi kipcole,

   I also live on a tidal river, in the USA.  I've been trying to find a way to get power from it for 3 years.  My river is also rather large (probably 0.5 to 1 km wide).  I've measured the flow, and do get tidal outflows up to 1.0 m/sec.  Even with this there really isn't any significant power that I can figure out how to harvest.  I'm also located about 30 meters above the river, so I also have a 'hill' challenge.  

   If you can dam it up, you can get large flows twice a day. Or even if you have a bay you can put a barrier across, you can get flows.  But usually this is not feasible (or allowed).  

   My only other thoughts now are to think about using the temperature differential between the river and the air.  Not sure there is anything worth harvesting this way, but something to think about (in the winter the river does not go below 40 degrees F, while the air will get down 0 degrees F.

   Sorry I don't have any better ideas for you.