|Shitao, Ling - WEST TEXAS A&M UNIVERSITY|
Submitted to: Windpower
Publication Type: Proceedings
Publication Acceptance Date: April 28, 1998
Publication Date: N/A
Interpretive Summary: It is estimated that approximately 500,000 mechanical windmills are still being used to pump water for farmers and ranchers in the U.S. Many of these aging windmills are over 50 years old and are becoming more and more costly to maintain. At the USDA-ARS Conservation and Production Research Laboratory near Bushland, TX, wind-electric water pumping systems have been ntested for the past ten years as a possible replacement for some of these aging windmills. While much has been learned about these systems at the laboratory, testing these systems at remote field locations should show whether they will be successful. A 10 ft diameter multibladed (15 blades) windmill had been installed at a remote location on some USDA land near Bushland, TX, about 60 years ago, and was basically worn out. Some federal and state animal researchers wanted to use the land to conduct a experiment with 75 cattle. Replacing the mechanical windmill with a wind-electric water pumping system was deemed the most cost-effective solution. The wind-electric water pumping system consisted of: a 1.5 kW (10 ft diameter, 3 blades) wind turbine, a guyed lattice tower, a pump controller, a 1.5 hp submersible motor, and a centrifugal pump. Flexible plastic pipe was used to replace the drop pipe and sucker rod in the 300 ft well. After six months of operation (Oct.'97 to Mar.'98), the wind-electric system has pumped more than enough water for the 75 cattle. The wind turbine, submersible motor, and the centrifugal pump have not caused any downtime during this time. The pump controller caused some downtime, but changes to the controller have eliminated the cause of this downtime. Another finding in this testing was that an hourly distribution of wind speeds (not just average wind speed) was needed for daily water volume prediction.
Technical Abstract: A wind-electric water pumping system was installed in September 1997 in a 73 m deep water well near Bushland, TX, for the purpose of providing water for 75 head of cattle. A wind-electric system was deemed the most economical way of replacing a broken 3.05 m rotor diameter multi-bladed mechanical windmill which was installed at this well site about 60 years ago. The wind turbine (3 blades, 3.05 m rotor diameter) used for this wind-electric system had a 1.5 kW rating at a 12.5 m/s wind speed and used a permanent magnet alternator, which produced variable voltage and frequency, 3-phase, AC electricity. The controller for the turbine was a newly designed, smart controller, that connected and disconnected the pump load and added capacitance to improve the power factor of the system, eliminating the need for an inverter. The submersible motor and centrifugal pump used were not specifically designed for this wind turbine and are readily available worldwide. Data collected from the wind turbine included: frequency, voltage, current, and power. Data collected from the wind-electric system included: wind speed, flow rate, water volume, air temperature, and battery voltage. This wind-electric system performed very well during the six months of testing and provided enough water for at least 80 head of cattle.