How Does a Wind Turbine Pump Water?

We've all seen windmills out in the country and watched as their operations are explained on TV. There's a peaceful aura about them, much more so than their electrical grid cousins.

Most people understand their use in generating electricity. However, many aren't aware that windmills were once used to grind grains as well as being used to pump water. How do windmills pump water?

How Long Have Windmills Been Used?

Windmills have been used since the first century AD. They were invented simultaneously by the Chinese and Persians. European models began around 1100 AD.

They were significantly different from their Middle Eastern and Chinese brethren. It was the Dutch, though, that built towers for their windmills. The 19th century saw 30,000 in use.

It wasn't until 1854 that a young Connecticut mechanic named Daniel Halladay built one whose sections could be moved and put together at its destination. His windmill would turn its own face to the wind by using the tail behind the blade.

If it spun too much, a weight on the tail would turn the blade slightly so it would slow of its own accord. In 1886, another inventor curved his blades in order to catch more wind. The design is used to this day, both in wood and metal blades.

Water pumping windmills were used to irrigate crops, water the gardens, and water the livestock. Holding tanks provided drinking water for farm workers and the family.

Windmills were a big deal in the early 1900s. Farmers with windmills from Sears costing $25 enjoyed some notoriety. Poor farmers had to make one themselves.

The three windmill manufacturers at that time are still in operation today: Aermotor, Dempster, and Baker Monitor.

How Do Windmills Pump Water?

What we see when we spot a windmill is the tower and 15 to 40 blades whirling in the wind. It's the equipment we don't see that pumps water. Inside the tower is a pipe leading to the well.

The windmill blades turn in the wind on a wheel to which the blades are attached. As they spin, they turn a rotor. The whole wheel is attached by arms to a hub.

Gears inside the hub morph rotary motion to up and down motion. The up and down motion moves a pump rod called a sucker rod up and down the pipe we discussed above.

On the bottom of the pipe is cylinder containing a sealed plunger. It goes up and down, forcing water up the pipe. Upstrokes pull water into the cylinder.

A check valve on the bottom engages on each downstroke. Water can't be pushed out, so it has no choice but to go up with the next upstroke. Each upstroke deposits water into a holding tank.

How Much Water Is Pumped?

Your basic windmill with a six to eight foot diameter of the wheel whirling in a good wind of 15 to 25 mph pumps around three gallons per minute. The quantity is around 1,500 gallons per day.

Alternatively, a ten to twelve foot wheel would have a higher pipe. Whirling in an eight to twelve mph wind, it would pump about 4,500 gallons per day or close to one million gallons per year.

Wind speed is vital to windmill operation. Puffing breezes won't get the windmill spinning. Winds above 25 mph, however, engage the mill's control system or the tail to slow the blades. Controlling the blades also means less water pumped, but it protects the mechanism.

Water pumping capacity is governed by more than just wind speed. The number of blades adds to the sensitivity it takes to get them turning in whatever wind is present. The diameter of the wheel as well as the cylinder size in the pipe and amount of water in the well all affect the output.

How Do You Maintain Your Windmill?

If you're not the mechanical type, it would pay you to hire a professional to maintain your windmill. It involves ten weight oil and/or automatic transmission fluid for greasing the gears. The seals on the cylinder need to be greased at the same time which is once per year.

Something called a “stuffing box” should be repacked and the nut tightened every now and then. As the pumping rod moves up and down, it moves through a hole in the stuffing box. The packing in the box lets enough water through to lubricate the pipe as it moves up and down.

Without the stuffing and lubrication, there would be metal on metal rubbing. This would wear out the rod. The cylinder plunger would react the same without its seals. So the box needs to be re-stuffed weoleith graphite rope and the cylinder seals greased once per year.

Conclusion

Here at Eole Water we believe that homeowners wishing to be more self-sufficient and green should use methods to pump water that have nothing to do with municipal water supplies. Windmills are sustainable, and they pump water not only to the house but to the crops, gardens, and livestock as well.

Windmills have been used world-wide for a couple thousand years. They require little maintenance. They're tried and true instead of being modern, new-fangled machinery.