Wind Powered Water Pumping

Wind Powered Water Pumping (Windmills)

Windmills (or windpumps) were once widely used throughout the world. The decline of the windmill was due to the most part from rural electrification in the areas that utilised them most. In modern times windmills still are an economic and practical solution to water pumping in many regions and are used to supply water to livestock on many farms and outback stations in Australia. These windmills, made by a variety of manufacturers, feature a large number of blades so that they would turn slowly but with considerable torque in low winds and be self regulating in high winds. A tower-top gearbox and crankshaft converts the rotary motion into reciprocating strokes carried downward through a pole or rod to the pump cylinder below (Wikipedia, 2007). The water is often pumped from the ground into a storage tank that provides a gravity feed to a trough for drinking.

Figure 1 Windmill pumps water on an Oklahoma farm
(Image © 2005 Oklahoma Farm Bureau).

Benefits and Performance

Windmills have been a traditional technology used to pump water for livestock, plants and humans. Pumping water using windmill technology is simple, robust, reliable, and requires almost no maintenance. This technology is cost competitive with solar photovoltaic technology. One major benefit of this form of technology is the low wind speeds needed to pump relatively large volumes of water. Typically windmills can pump water with a wind speed of 3 to 4 metres per second, which occurs in sufficient instances in most places to warrant the use of such technology. For an article written by Australian Windmill Contractors on Windmills versus Solar Photovoltaic pumping systems click here.

Constraints

Unfortunately in the hottest times of the year there can be a lack of wind. With insufficient storage tanks to supply water during these periods the windmill and storage system may not be able to supply the drinking water that animals need and water carting may be needed if possible. However this can be overcome by a good knowledge of the climate and designing the system for such conditions.

Sizing a Windmill Pumping System for Your Needs

Windmills for Stock and Domestic Water Supplies (pdf) written by the Queensland Department of Natural Resources, Mining and Water provides a good example of outputs and windmill sizes for your water requirements.

Calculate your Total Dynamic Head using WD Moore’s TDH page

Costs

Costs will vary depending on the type and size of the windmill needed to supply your water requirements. See the “Links to Suppliers and Further Information” section for a quote from suppliers and manufacturers.

Conclusion

Wind powered water pumping is an extremely reliable, robust and cost effective technology for remote area pumping with no access to the electricity grid.

Links to Suppliers and Further Information

RISE Resources - Information regarding available renewable energy resources.

RISE Technologies - An extensive collection of information regarding renewable energy technologies.

RISE Applications & System Design - Renewable energy application information and system designs.

RISE System Displays - Case studies and information on installed renewable energy systems & performance data.

Wind Energy Manufacturers in Australia

Geocities Windmill Supplier Information (at the bottom the page)

Renewable Energy Information Network’s (REIN) Water Pumping Windmill Page.

References

Wikipedia, 2007. “Windmill” (Online) http://en.wikipedia.org/wiki/Windmill (Accessed 28 February 2007).