Using wind energy to pump livestock water

Windmills are classified as vertical or horizontal axis machines depending on the
axis of rotation of the rotor. Vertical axis wind- mills can obtain power from all wind directions whereas horizontal axis windmills must be able to rotate into the wind to extract power Windmills are also classified as either electrical power
generators or water pumpers. Power generators are typically horizontal
axis “propeller” type blade designs or vertical axis “egg beater” designs. Power generators typically operate at high rotational speeds with low starting torques, appropriate for generators.

oints to consider when selecting a windmill:
1. First of all, a water source is needed, knowing the volume of water to be pumped
(livestock requirements) and the lift (from water level to top of tank)
• if using a well, it should be drilled first to know the lift and volume available
2. Some estimate of available wind must be made, preferably from site readings
• select a tower height
• adjust site readings to the tower height using Table 3
3. Choose the combination of cylinder size for volume and rotor diameter for lift
• use manufacturers tables or Table 2, page 3, for size estimates
• usually best to choose the largest rotor and smallest cylinder that will fill the
need, for easy start in lighter winds and minimized strain on the system
• as a rule-of-thumb, expect an average of 4 - 5 hours/day of pumping at the
specified rate for 24 kph wind unless local conditions are known
4. Other points:
• windmill pump outlets are normally discharged into an open tank i.e. into the
top of the tank - if the outlet is to go into the bottom of the tank or rises above
the well head a packer head is installed to seal the drive rod
• hand pumping can be done on some windmills in emergencies - the hand pump
is part of the installation and the operating handle is attached when needed