Well Water Pumping

Increasing the pipe size will decrease the friction and therefore more flow or less power.

The shaft power is only a little over 13W or so.

A pump of this low power that will cope with a lift of 700ft is as rare as a pile of rocking-horse fecal material.

I would parallel 4-6 big car or truck batteries and then use a big DC to AC inverter with a bigger high efficiency pump and hope that it doesn't need to run very much.. If it does... just keep adding batteries!..

I get these huge 900/1000 amp batteries from costco for about $60 bucks?.. They work for my little projects.

While solar powered water pumps are usually effective at low flows, I've never seen one that could develop enough head to life water 700+ feet. That is a fairly deep well to only require an output of 5 gph.. I'm curious, what is the purpose of the well? Is it for water effluent testing for environmental monitoring purposes?

Using low voltage submersible pump, your electric supply cable is going to be nearly 3/4" bore. Suction just isn't going to work. And 1000 Amp hour batteries for 60 dollars, there must be a downside.

How was the well dug, and what was the original water extraction method?

Looks to me like a use for the original horsepower pulling up buckets, still solar, sun makes grass grow, grass makes horse go.

Simon

But is the depth--notice I say depth, not height--going to affect things like you folks seem to be saying? As if the water were being pumped upward to a tank? Would not the weight of water (the gravitational attraction between water and Earth) actually decrease with increasing depth within the crust? Is this something which should be taken into account before answering? Just curious.

as they say when falling off 700 foot towers, it 's not the 700 foot that kills you, it's the last millimetre that does the damage. Even if the gravity at the bottom was significantly less, only getting water halfway up, or even 99.99% of the way up is 100% useless. It's that killer last millimetre again.

Simon

Doesn't the low volume of water being pumped offset the head pressure? The total volume of water in a 3/8" tube would not weigh but a few pounds. What would the total head pressure be at an open flow?

If the resistance of the wire would be too significant for DC the current could be converted to AC while still using low flow. Would it not be more cost efficient to pump small volume at a constant rate rather than intermittently pumping huge volumes requiring higher energy consumption and bigger equipment?

These pumps would be used to supply water in areas that do not have access to the grid and do so at a much more reasonable cost.

I would guess that the best way is to have several pumps spaced through the 700', assuming that you can get to such positions to place them in the first place.

700' is a long way vertically.....probably you will need 5 pumps or so......just guessing!!

If you can only power one at a time, make each pump to fill a header tank above it, when full, that switches that motor off and the next pump, pumps to the next header tank and so on.....

Should be easy to organize with some float switches and some simple logic....

...just a thought!!!

What is the diameter of your well casing? For that deep a well, it must have been drilled and cased. How much does the water level vary?

Just out of curiosity, what was the original purpose of drilling the well, and what is the use of the extracted water?

You might be able to do it with a small gear pump if it will fit down the well. How about some more detail on the application.

The well is a 6" cased well and is used for my home water. It currently uses a 1 1/2 hp submersible pump. The water level stays about 590 to 620 feet and the well is capable of about 3.5 gpm. I often have trouble with maintaining electrical service and would like to replace the 220 v.ac pump that runs maybe twice a day (during heavy usage) to refill the cistern, with a lower power pump that runs constantly and can be dependable with solar/battery power.

I began thinking about this when replacing a fuel pump on a car. Some of these pumps are capable of 80 psi and can maintain a constant flow of 5 gph. I am not an engineer but think that a low, constant flow pump should be able to provide the water I use much more efficiently than a high powered - high flow pump used once in a while. The same total energy would be used but instead of using a huge amount for a few minutes I would use a small amount over a longer time.

Can anyone tell me what the head pressure would be at 5 gal/hr. through PEX (cross-linked polyethylene) tubing for 600 to 700 feet of lift?

From your last post:

"Can anyone tell me what the head pressure would be at 5 gal/hr. through PEX (cross-linked polyethylene) tubing for 600 to 700 feet of lift?"

This question first. A cubic foot ot water weighs about 64 pounds. There are 144 sqare inches in a square foot, so 64/144=0.44 PSI/foot. At 650 feet, that's a pressure of about 290 PSI before adding the line loss from the piping.

One complication for your project is the variation in the water depth. A pump can only draw from about 20 feet, so you would need to have a submersible pump. I don't think that you would want to try to design one yourself. Most deep well submersible pumps are designed for only 300-400 feet of lift. There are pumps made for deeper wells, but they run many thousands of dollars.

You have probably considered this already, but how about a small gasoline powered generator to drive your existing pump during power outages? I suspect that would be considerably less expensive and less of a hassle than replacing your pump. You would only need to run it when you ran out or water.

Alternately, you could use a battery bank and inverter. The batteries could be kept charged with a battery charger from your 220 AC power, or from a solar array if the power was out for a long time.

Would pressurising the air in the shaft force water UP a narrow bore pipe in the cased shaft? Then you could have all the kit at the top. This is probably a dumb question, but it is a genuine one.

Simon

ab72756,

Andy stated in post #9 a suggestion to run several pump in line switched. I suggest use Andy's multiple pump model but use DC motors and daisy chain them to all pump together. Then you should achieve your ends and having a closed tank to release a certain volume into the cistern could aid also.

.

Post #12 suggests wind driven pump action, a steady 8+mph wind would suffice.