Submitted to: Windpower
Publication Type: Proceedings
Publication Acceptance Date: 6/28/2000
Publication Date: 9/30/2000
Citation: Vick, B.D., Clark, R.N. 2000. Testing of a 2-kilowatt wind-electric system for water pumping. Windpower 2000, Palm Springs, CA. 2000. CDROM.
Interpretive Summary: Using wind energy to pump water from underground wells is not a new concept to U.S. farmers and ranchers since they have been doing this for over a century with mechanical windmills and piston pumps. The USDA-ARS Conservation and Production Research Laboratory has been investigating a fairly recent concept for using wind energy to pump water. Instead of windmills to produce mechanical power to drive the piston pump, wind turbines are used to generate 3-phase AC electricity for powering submersible motors to pump water from underground wells. This wind-electric system is an improvement over the mechanical windmills in that much less maintenance is required and the wind-electric systems perform much better at moderate to high wind speeds. A new 2-kilowatt wind turbine design was tested for pumping water from February to October at the USDA-ARS laboratory. On April 14, 1999, the wind turbine suffered extensive damage in 45 to 55 mph wind speeds due to deficiencies in the wind-electric system design. The manufacturer performed a complete redesign of the wind turbine in two weeks and testing on the redesigned turbine began on April 29, 1999. Other wind-electric system modifications were made during the next three months which maximized performance without degrading reliability. This testing was very important because the manufacturer of the wind-electric system learned he needed to modify his wind turbine design to keep the wind turbine from being damaged in high winds. The farmers and ranchers were benefitted by getting a more reliable water pumping system which was shown to have good water pumping performance at both a 100 ft and a 240 ft water well depth.
Technical Abstract: A 3-bladed 3.3 meter diameter upwind horizontal-axis wind turbine rated at 2 kilowatts (kW) for a wind speed of 11.5 meters/second (m/s) was tested at the USDA-ARS Conservation and Production Research Laboratory from Feb. 2, 1999 to Oct. 11, 1999. The wind turbine achieved its 2 kW rating (sea level standard day conditions) at a wind speed between 11.5 and 12 m/s. Four different tails and two different yaw axis offsets were tested becaus the furling behavior of this wind turbine was critical to its success. Two different sets of blades with different pitch angles were also tested to determine the optimum pitch angle. The primary controller used during this testing was an ARS/AEI designed controller, but the manufacturer's controller was operated for a period of two weeks during July and performed well. Using a low head pump, a peak system efficiency of 12% was achieved at a simulated 30 m pumping depth. For a high head pump, a peak system efficiency of 8.5% was achieved at a simulated 73 m pumping depth. Both water pumping systems had a cut-in wind speed of 5 m/s.