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Large Wind Turbines

May 23, 2003
Paul Gipe

Brazilian Tests Confirm Air 403 Underperforms Power Curve

Gustavo de Marsillac Peña presented the findings from a series of laboratory tests on an Air 403 at the American Wind Energy Association's annual conference this week in Austin, Texas.

The tests at the Nucleo Tecnologico e Meio Ambiente, part of the Catholic University of Rio Grande del Sul, confirm measurements made previously at a California test field. Señor Peña conducted the tests as part of a master degree program in electrical engineering.

Southwest Windpower's Air 403 is a micro turbine ostensibly rated at 400 watts. The unit is no longer manufactured and has been superseded by the AirX.

The Brazilian tests were made under controlled conditions in a laboratory. Measurements of the Air 403's power curve has been extremely controversial in the United States, where thousands of the units have been sold.

Previously, performance of the Air 403 had been measured at the Wulf Test Field in California's Tehachapi Mountains. These measurements had shown that the turbine significantly under performed the manufacturer's advertised power curve. The manufacturer dismissed the measurements made in California because of presumably high turbulence at the hilly site.

Señor Peña reports that the California measurements showed the Air 403 producing 300 watts at 12 m/s. His results indicated that this was slightly optimistic and that the turbine produced 300 watts at 13 m/s. The manufacturer advertised that the turbine would produce 400 watts at 12.5 m/s.

For more information contact Señor Peña at

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