Submitted to: Windpower
Publication Type: Proceedings
Publication Acceptance Date: 6/23/1999
Publication Date: N/A
Citation: Vick, B.D., Clark, R.N., Ling, S. 1999. One and a half years of field testing a wind-electric system for watering cattle in the Texas panhandle. Windpower 1999. Burlington, VT. CDROM 1999.
Interpretive Summary: A 1.5 kW wind-electric system has been field tested at the USDA-ARS laboratory in Bushland, TX for watering cattle on open range land during the past 1.5 years. The wind-electric system consisted of a 1.5 kW wind turbine, a smart controller, a submersible motor, and a centrifugal pump. The 1.5 kW wind turbine has a 10-foot rotor diameter (3 blades) and generates variable-voltage, variable-frequency, 3-phase AC electricity wit a permanent magnet alternator. The ARS designed controller is able to connect the wind turbine to a standard submersible motor/pump combination and maximize the daily water volume (cost of controller only $400). This wind-electric system was used to replace a broken down mechanical windmill with a 10-foot rotor diameter (15 blades) that was installed at the USDA-ARS laboratory in 1939. The wind-electric system has been able to pump enough water during the fall, winter, and spring to satisfy the water requirements of 80 head of cattle. However, during the low wind months of July and August, the wind-electric system has only been able to satisfy the water requirements of about 40 head of cattle. An analysis of the replaced mechanical windmill indicates that the mechanical windmill would have satisfied the water requirements of 80 head of cattle during the whole year including summer. An analysis of wind data gathered at several heights at a nearby location indicates the wind-electric system pumping performance could be doubled during the summer (i.e. would be able to pump enough water for 80 head of cattle) if the wind turbine tower height was increased from 60 to 100 feet. This substantial increase in performance is due to the fact that the wind speed increases as the height above the ground is increased which results in more electrical power generated by the wind turbine.
Technical Abstract: A wind-electric water pumping system was used to replace a multi-bladed mechanical windmill for watering cattle on USDA-ARS range land near Bushland, TX. The multi-bladed windmill had 15 blades with a rotor diameter of 3.05 m, and powered a 4.8 cm diameter piston pump. The wind turbine (3 blades, 3.05 m rotor diameter) used for the wind-electric system mhad a 1.5 kW rating at a 12.5 m/s wind speed and used a permanent magnet alternator to power a submersible motor with a 10 cm centrifugal pump. Over the past 1.5 years the wind-electric system has been able to pump enough water from a 73 m well to satisfy the water requirements for 80 head of cattle during the fall, winter and spring. However, only about half the water needed for the 80 head of cattle was pumped by the wind-electric system in the summer (July and August). An estimate of the mechanical windmill showed it would have pumped enough water to satisfy the water requirements of 80 head of cattle during the entire year. Theoretical analysis of the wind-electric system suggests that the water volume should be high enough for summer if the tower height is increased from 18.3 m to 30.5 m -- this will also add an additional $1000 to the cost of wind-electric system.