Bergey Windpower News

NREL Tests Document Low Noise from Bergey Turbines

November 15, 2003

In a technical paper to be delivered at the 23rd ASME Wind Energy Symposium in January, the US-DOE's National Renewable Energy Laboratory (NREL) shows that Bergey 1 kW and 10 kW wind turbines rank well against other American wind turbines for low noise.  In fact, the 1 kW BWC XL.1 was the quietest turbine tested, even though it was not the smallest turbine in the test program.  The NREL tests also document the significant noise reduction that Bergey Windpower has achieved with a new rotor design for its 10  kW turbine.

The technical paper "Acoustic Tests of Small Wind Turbines", authored by Paul Migliore, Jeroen van Dam, and Arlinda Husky, will be presented January 5-8 2004 in Reno, Nevada.  A copy of the full paper (PDF, 700 KB) is available by clicking here.

The NREL noise tests included products from Bergey Windpower, Southwest Windpower, Northern Power, and Atlantic Orient Corp. (now a Canadian company).  The tests were performed using the IEC international standard and the results are presented for both the noise volume right at the wind turbine (sound power level) and at a specified distance from the turbine (sound pressure level).  The results are presented against background sound levels and in some cases the test data could not distinguish between the turbine noise and the background noise.  

This was particularly true for the Bergey XL.1.  For the XL.1 the NREL technical paper states "The measured values are quite low and the apparent sound power level at 8 m/s cannot be reported because the turbine noise level could not be separated from the background noise."

Probably the best product-to-product comparison available in the technical paper is the apparent sound power levels at a wind speed of 9 m/s (20 mph), as provided in Table 1 of the paper.  These results are summarized below for current production models.  Please note that sound power level can not be directly compared to the noise scale used in municipal noise ordinances because it does not take into account the reduction in noise level as you get farther away from the noise source.

Brand Model Rated Power Diameter Rotor Area Sound Power Level*
Southwest Air X 400 W 1.1 m 1.0 m2 81.3 dB
Southwest Whisper H40 900 W 2.1 m 3.5 m2 87.4 dB
Bergey XL.1 1,000 W 2.5 m 4.9 m2 75.8 dB
Bergey Excel 10 kW 6.2 m 29.9 m2 92.3 dB
Atlantic Orient Corp. 15/50 50 kW 15 m 177 m2 101.9 dB
Northern Power NW 100 100 kW 19.1 m 287 m2 95.1 dB

The NREL technical paper makes the point that small wind turbine manufacturers have made product improvements over the past few years that have significantly reduced the noise emissions from their products. "We're pleased to see our products rank so well in the first comprehensive noise test of U.S. small wind turbines.  We have put quite an effort into noise reduction in the last five years and we have made good progress.  We will continue to make low noise a priority in our R&D program" noted Mike Bergey, president of Bergey Windpower.

 
For further information, please contact:

   Steve Wilke, Customer Service, Bergey WindPower Co.

   T:  405-364-4212    F: 405-364-2078    E-mail:  swilke@bergey.com