The depth of a well and the height of the water in the well alone with how much water you think you will need to pump per day are some deciding factors in what kind of pump you need.
The old farm windmill will pump in much lower winds then any wind generator. So if you are in a low wind area that's an important factor. They work by a multi blade prop driving a geared down crankshaft which lifts a rod up and down. This rod runs to the bottom of your well in the inside of the pipe. At the bottom of the well it works a ultra reliable piston pump to pump the water. This kind of pump can pump up to 900 feet depths perhaps deeper. Then can also pump from shallow depths.
South Africa If I'm correct ? Produces a windmill that uses a rotary pump that is said to be ultra reliable. I believe it's actually manufactured now in China, but there is an American dealership for it.
If you wind isn't what it should be, you can pump water with the above deep well pumps, but instead of the windmill, you use what's known as a " jack pump" some say " pump jack" driven by a small motor. This can be driven with commercial power or solar power. Because the motor sets above ground, it's easily serviceable.
Here's a museum in Canada that shows most wind mills that have been manufactured over the years, many of which are still manufactured. It's a fun site to re-call the olden days to ; )
http://frontpage.execulink.com/allenmott/Windmill%20List.htm
I grew up on a cattle ranch in Colorado where we could reach minus 40 degs, under total "white out" blizzard conditions. Very severe weather to say the least. The old water pumping windmills are about the most reliable method you can find to pump water through the severest of weather.
The "old farm windmill" as they are often called that I mentioned above can be bought used throughout most of the Midwest of America, The are quite expensive new ( in my opinion. ) But they will last 75 to 100 yrs or more with good care. The well cylinders can be re-built over and over.
Other options are the "Bowjon" pumping methods ( using air compressors driven by wind or pv). My brain is a little rusty, but I think you have to use 100 feet of water in your well to pump 33 feet etc. So how ever deep the water is in your well, it will only pump water to 1/3 that amount above the water line using the bubblier method. Some one please correct me if I'm off on this, but I think this is the math on that. There are several units on the market. And my brother has built the bottom units. I own one right now. The submersed portion is simple to build.
The Amish also manufacture a cylinder that has a float inside of it. The cylinder is submersed under water in your well. A one way check valve allows it to fill with water. When it is filled, the float comes up against the top of the inside of the cylinder and trips an air valve that allows pressurized air to force the water down and out the bottom of the cylinder, and up to the top of the well. This causes the sliding float to fall to the bottom of the cylinder, and it trips a mechanism that releases the air out of the cylinder, and allows it to once again fill with water to begin the process all over again. If you have a shallow well, this method will allow as an example, a 500 gallon tank of air pressurized to 130 psi to have the stored capacity to pump say 1,500 to 2,000 gallons of water. But as the depth of your well is increased, the performance drastically drops off. But this works splendid on shallow wells.
I Own one of these pumps new never used.. Gave about $475.00 for it and never used it because I discovered my well was too deep so need to sell it or trade it off probably.
Then there are 3 phase wind generators direct driving commercial 3 phase submersible pumps. If you have higher winds, and want a lot of water, this is a very good way to go. The pumps are " off the shelf 240v 3 phase pumps" And Whsiper, as well as Bergy sell the wind generator heads. As your Wind machine slowly starts turning, so does the motor in the bottom of your well. Finally as your wind machine reaches sufficient speed, your pump will start reaching the necessary rpms to get the water to the pump. You size your submersible pump with extra stages of impellers, so it has higher pressure. This gives it a larger window of wind speeds that it can pump from. You do not need to worry about burning your motor out with low voltages, because the pump motor's power factor tracks your wind generator's alternators frequency. If you wind plant is just setting their idling in a light breeze, your pump motor will be turning very slowly, but will not be over heating.
There are other pumping systems as well... I covered just a few.
Email me if you wish with the details, and I can give you more detailed information.
I live on a farm, and am not affiliated with any water pumping businesses.
Email: jjones2(at)inter-linc.net
John II
