Using the Noise Perception Index (NPI) for assessing wind turbine noise

摘要

The author has recently published a detailed noise impact assessment methodology in the Noise Control Engineering Journal intended for conventional facilities and power plants. The method averages on an energy basis the hourly increase-to-ambient caused by a planned or existing source over a representative minimum length of time to predict the long-term perception and response from adjacent communities. The core foundation used to justify the method is decades of successful experience gained in two States in the U.S. that use the increase-to-ambient or ambient-based approach for permitting facilities. The ambient basis for NPI is the daily minimum hourly LA90 measured typically during calm & still wind conditions. This paper explores the applicability of the NPI method for wind turbine generators (WTG) that only operate during windy conditions. NPI was calculated for a completed and planned installation. The results of NPI predictions appear promising for assessing WTG noise on a long-term equitable basis.