For me noise is the largest issue, and consequently the one I’ve spent the most time researching. I go into more details below and in additional posts, but if you don’t want to wade into them, experience has shown that wind turbines can be much louder than advertised. In Ontario, for example, when the complaints come in and actual measurements are taken, the projects have always been out of compliance, page 8 with Ontario’s rules. It seems to depend on the conditions, and the unfavorable conditions can be quite common. Generally North American jurisdictions do not provide adequate protection for homeowners, and as new projects are brought online the number of complaints and people being forced out of their houses is growing alarmingly.

The claims and counterclaims are fairly far apart. This is surprising to me, as sound generation and propagation are not new fields of study. Perhaps the divergence occurs due to one’s interpretation of “nuisance” or “annoyance” or “health effect”. While the wind industry generally concedes there will be audible noise, they minimize the nature of the sound, saying it more or less blends into the background within 1000 feet, or 350 meters.

Wind proponents tend to cite studies that model the sound levels and then cite government noise regulations that would indicate the noise created is legal and thus assumed to be safe. The wind power opponents counter this with a list of horror stories where people actually living close to farms have suffered to the point that the home becomes uninhabitable, including health effects. There have now been tens of thousands of turbines installed around the world. I’ve read reports that estimate 10-20% of projects have noise issues, and these reports – all recounting similar symptoms – come from around the world. All these reports cannot be due to jealousy or Nimby-ism. Every other year there is an International Wind Turbine Noise Conference. The last one was in June of 2009 and Bill Palmer attended and wrote up this report. It is interesting to note the differences between the European and the North American experiences.

While a turbine makes all sorts of mechanical noise, it is generally the “swoosh” of the rotors as they rotate that seems to draw the most attention. I suspect the other noises fade out pretty quickly as you get further from the tower. The swoosh, on the other hand, can be heard quite a distance away, up to several miles, and it seems that weather conditions affect this greatly. Many people have visited wind farms and generally don’t think they make much noise. That observation is generally made over a period of a few hours at most, during the day, and from right at the base of the turbine. The complaints from residents are generally over extended periods, during the night, at some distance when they’re trying unsuccessfully to get to sleep. I have come to trust only the reports from non-participant residents who have spent an extended time within 1 km of a turbine. It’s not that I particularly distrust the participants, it’s simply that they may be contractually restricted in what they can say.

Most governments have long-standing rules about noise. But the path from having rules to actually operating a benign wind farm is so long, uncertain and subject to manipulation that I’ve created a series of pages in an attempt to present all the wrinkles in an understandable manner. While the information in this series is generally applicable to all locations I will be using mostly Ontario as a real example.

General References

Each of my other noise pages has additional references particular to that section.  These are more general-purpose.