Wind powered water pumps

[DenverDave]

What is the state of the art for wind powered water pumps (used to be called windmills)?    I'm mostly looking into water powered water pumps, but in some situations like when water is in a well, it may not be feasible to power with water, but wind would seem to be an option in some locations, especially when electricity is not available.

Ideas?

[Adriaan Kragten]

In my report KD 490 I give an overview of several options how water can be pumped with a windmill. This report can be copied for free from my webside: www.kdwindturbines.nl at the menu KD-reports.

[Bruce S]

What is the state of the art for wind powered water pumps (used to be called windmills)?    I'm mostly looking into water powered water pumps, but in some situations like when water is in a well, it may not be feasible to power with water, but wind would seem to be an option in some locations, especially when electricity is not available.

Ideas?

You might look into the tractor/farm supply stores, around here they still sell the old style large mills that dotted the lands a few decades ago.
Buchheits doesn't show them in their online catalog , but they had a few outside the store we frequent. A visit to any close by you, or a call could help with locating one.

Hope this helps
Bruce S

[bigrockcandymountain]

Honestly by far the best is the old chicago style that have been around for a hundred years.  The one still produced is an aeromoter 701.  It uses a piston pump down the well etc.  We use them to water cattle so they need to be very reliable. 

The other option is a wind turbine charging batteries and then a well pump.  Solar works better for this in our area. 

Adriaan has some ideas that he posted for a wind turbine electrically direct connected to a well pump.  This may work too but i have no experience with it.  I would suggest a positive displacement pump rather than a centrifugal if you go this route.

Sorry no new breakthrough that i can think of.  Hopefully someone else has something.  I would love to know about it too.

[Adriaan Kragten]

There is a breakthrough to increase the output of a traditional water pumping windmill with a single acting piston pump and that is to use a floating piston valve. This idea is described in my public report KD 364 and in old CWD-publications. It has been tested in practice on the CWD 2000 windmill in 1989 at the University of Technology Eindhoven and it worked really nicely.

At low piston speeds, the hollow valve is floating and no pressure is built up above the piston. The windmill rotor therefore starts really easy. As starting is now no longer a problem, a much bigger pump can be used which results in a much larger output at moderate and high wind speeds. One can also use a rotor with a lower starting torque coefficient and so with a higher design tip speed ratio and lesser blades. Therefore the rotor becomes lighter than the multi bladed rotor of a traditional water pumping windmill with the same rotor diameter.

The floating valve closes at a certain water speed in between the valve and the valve seat. This water speed happens at low rotational speeds just half way the stroke. So the stroke volume at low rotational speeds is just half the theoretical stroke volume. But at high rotational speeds, the valve closes only a little after the bottom dead center. This increase of the stroke volume results in increase of the average torque level and therefore in a much better matching with the rotor than for a pump with a constant stroke volume.

[MattM]

Piston pump rather than a lift pump?

[Adriaan Kragten]

Do you mean a rope pump with a lift pump? The option of a rope pump combined to a windmill is described in report KD 490. An advantage of a rope pump is that the flow and the torque are not fluctuating and that the rising main empties after a certain time when the windmill isn't running. This facilitates starting of the rotor even if it has a rather low starting torque coefficient. The disadvantage of using a rope pump in combination with a windmill is that you need a transmission with a rotating vertical shaft in the tower. The windmill rotor needs an eccentricity because of the safety system and therefore you need a special transmission to go from the rotor shaft to the vertical shaft. A promising simple option using a round string and only one auxiliary wheel is given in report KD 320. The rope pump is described in report KD 321. You need a second transmission to go from the vertical shaft to the horizontal shaft of the rope pump but as there is more space at the tower foot, there are more simple options for this second transmission.

[midwoud1]

Windmill water-ropepump Nicaragua

  https://www.youtube.com/watch?v=E1qIdvH1bvM 

 Has to be improved by a vertical shaft , two 90 deg gearboxes  and a brake

[Adriaan Kragten]

The windmill on the video has a so called hinged side vane safety system which is also used in my VIRYA windmills. The rotor is placed eccentrically to make that the rotor turns out of the wind at high wind speeds. There is a rope transmission in between the horizontal rotor shaft and the horizontal pump shaft but this works only if the maximum yaw angle is limited other wise the rope will run from the wheels. So this transmission is only possible for regions for which the wind always comes from the same direction. As the rotor has an eccentricity it isn't possible to use a rectangular gear box in the tower top.

[Mary B]

I remember a wind driven water pump growing up. At a family friends farm. It used a vertical rod that pumped up and down and was driven from a gearbox up at the top. I remember pulling the pump rod from the well and replacing the leathers on it. It was basically an upsized hand hydrant pump design...

[wlcoldiron]

I have been playing with pumping water since 1980. I made a air operated pump from pvc. It's 150 ft. below the ground.It takes 40psi. to pump water. It now pumps about 12-14 gal per minute. In the future I plan to have a windmill tower 40' with a compressor turned by the wind. I have a dim view of electrical providers. When I get the system all together I'll be able to pump water 24/7 and have air to operate the air tools.
 

[XeonPony]

look up bubble pump, it uses compressed air to lift the water, from there any sort of pump you fancy for distribution, not so ideal for cold environments though.

https://en.wikipedia.org/wiki/Airlift_pump

[Adriaan Kragten]

Technically an air lift pump is a simple design without moving parts. However, it has some big disadvantages.

The first is that the overall efficiency of pump and compressor is very low. The efficiency of the air lift pump itself is about 50 % but the efficiency of the compressor is even lower because a lot of heat is generated during compression.

The second is that you need a well which is much deeper than the water level. This is because the air has to be inserted far below the water level to make that the pressure in the rising main at the point of insertion is less than the pressure in the well at the chosen water depth. If the height in between the water level and the reservoir is 10 m, the point of insertion of the air must lie about 10 m below the water level to get an acceptable pump efficiency. For this condition, the average density of the mixture of water and air bubbles is about half the density of water.

The third is that a 1-cylinder compressor has a very large peak torque. So you need a windmill rotor with a very high starting torque to get an acceptable starting wind speed. Another option is to open a valve in the compressor at low rotational speeds to make that the compressor runs about unloaded at low wind speeds but this needs a mechanism which opens and closes the valve at the correct rotational speeds.

When I was working at the Wind Energy Group of the University of Technology Eindhoven, I have guided a student who has spent four months to investigate the windmill driven air lift pump. The result of this study is given in report R 727 A but this report is in Dutch and no longer available. An air lift pump is only an acceptable option if you need only a little amount of water a day like for drinking water. For irrigation or drainage, the low overall efficiency will result in a very large rotor diameter for the wanted flow.

[Frank S]

I'm not so sure that everyone is on the same page in this discussion of wind powered water pumping from a well. Or the amount of water that needs to be pumped for that matter. I won't go into the numerous way to utilize the wind to extract water from a bore hole since there are many some more efficient that others. Double acting piston pumps in the bottom of the bore hole powered by a sucker rod would lift water on both the up and down strokes, a counter weighted pump jack would have the lowest starting torque requirement Oil has been pulled from the ground at depths up to  tens of thousands of feet using these for nearly 100 years while being powered by relatively small low power motors Even wind mills have been used to pull oil out of the ground
 Using the wind to power a compressor has been done many ways . Rotary screw compressors have a low start up torque and can produce large volumes of compressed air their 1 downfall is most need to rotate at well above 500 RPM preferably around 1000 to 2000 and require lots of lubrication which must be scrubbed from the air being compressed. dry vane rotary compressors also produce high volumes of  low pressure air but require vane replacement at frequent intervals
 Bellows compressors produce high volumes of low pressure air but only function in 1 direction. this leaves diaphragm compressors these will pump air in both directions their start up torque is dependent on the pressure already in the line. Also as with any other form of compressor an unloader valve can be incorporated allowing which ever type of compressor used to start up at low pressure.
 Enough about making air or which ever water pump method is used. Storage is the KEY Storing the air after it is compressed for later use or storing water after it is raised from the well just like storing electricity this is the absolute key to operational efficiency. Having large storage capacities reduces the need to have large amounts of on demand power to produce water from a well.
  Just like everything else the wind never blows when you need it the most and the sun only shines during the day time when ther are no clouds.
 A well may be capable of producing 12 to 14 GPM on demand but it is unlikely one can produce that amount for hours and hours on end day in and day out,nor can I think of why someone would need to use 17,000+ gallons of water every day even if they had a large heard of cattle.
 The thing to do is to calculate how much water is actually needed per day per week or per month then size the equipment accordingly. If you live in an area where the wind blows almost every day your total storage requirement may be less. Water is easier to store than to pump when the wind does not blow. Compressed air will only stay compressed if there is no leak age   

[Mary B]

Technology that works has been out there for well over 100 years... why reinvent the wheel?

https://www.youtube.com/watch?v=3AA8s3Jtetg

[Adriaan Kragten]

Every option to pump water with a windmill has some advantages and disadvantages. In my free public report KD 490 "Water pumping with a windmill" I explain why I think that development of traditional water pumping windmills with a single acting piston pump and a reducing gearing in the windmill head is not the best choice.