Did PacHydro give a free kick to the anti-wind lobby?

Yesterday wind farm owner and developer Pacific Hydro had the rest of the wind power industry scratching their heads in consternation. 

There on the front page of The Australian newspaper was an article stating:

People living near wind farms face a greater risk of suffering health complaints caused by the low-frequency noise generated by turbines, a groundbreaking study has found.

The study the newspaper was referring to was paid for by Pacific Hydro.

What caused the consternation was a combination of two things that suggested this study would reach a pre-determined conclusion which was always going to provide ammunition to support the claims of the anti-wind farm lobby, even where the evidence was weak:

1) The study was undertaken by acoustician Steven Cooper, who has an extensive association with anti-wind farm lobby groups that claim wind farms emit a form of low frequency noise known as infrasound which makes people sick. While Cooper himself asserts he is not anti-wind farms, he has at various points in time suggested that there is a likely noise problem associated with wind farms which requires changes to the regulatory regime, and that other studies dismissive of this issue are somehow corrupted or have been incorrectly conducted.

2) The study examined the possible effects of noise from the Cape Bridgewater wind farm for just three households of six people – all of whom have had long running complaints about the wind farm.

Members of the academic community have come out panning the study as inadequate and lacking in scientific rigour and saying that its findings would be rejected for publication in any half reasonable academic journal.

Some within the wind industry have privately criticised Pacific Hydro for almost being naïve. They've complained that even though it's obvious this study falls far short of the kind of rigour required to reach statistically valid conclusions, it is more than enough for wind farm opponents to sow doubt and create fear in the public's mind in spite of a range of health authorities (NSW, Victoria and Canada) dismissing the idea wind farms can harm human health. They point out that the fact that a wind farm company actually paid for the study will act as endorsement of the credibility of the study's claim that the wind farm is creating a form of harmful noise .

Yet if you take the time to look past The Australian newspaper article and read the study, it's possible to come to an alternative conclusion – that Pacific Hydro have done their industry and the community more generally a service.

In the end Pacific Hydro have just paid for the anti-wind farm lobby to take their absolutely best shot at identifying a causal link between wind turbines and health problems – and what they've come up with isn't terribly impressive.

Pacific Hydro could have insisted that the study look at possible noise effects on every one of the 62 households within 2km of the Cape Bridgewater wind farm, not just the three households who have strongly complained that the wind farm is doing them harm.

In addition the company could have insisted on an acoustician without any track record of views on wind farm noise. But in the end they accepted the aggrieved householders' choice of an acoustician highly critical of wind farm noise regulation.  

Now yes, the study's executive summary asserts that the wind farm does emit a very peculiar form of noise or vibration (that no one can hear, by the way) that Cooper believes causes the six residents to feel a “disturbance” or “sensation” including headache, pressure in the head, ears or chest, ringing in the ears, heart racing or a sensation of heaviness. According to Cooper this occurs at times when the wind turbines experience significant change in output – either up or down – or when wind speed is above 12 metres per second.

Yet in an interesting case of understatement the executive summary acknowledges: “...there were at times other instances of high severity of disturbance not fitting” such circumstances. Indeed the executive summary acknowledges that for one resident out of the six, sensation was observed when the wind farm was actually shut down.

Now if you turn to page 115 of the report you learn that there were 552 times when the aggrieved residents said they felt these sensations over the study period at a severe level of 4 or 5 out of 5. Of these 552 reported severe sensations, Cooper, for a wide variety of reasons of his choosing, excludes from consideration 491. This leaves just 31 reported sensations rated 4 or 5, or just 6% of the sample for which Cooper derives his conclusion that the wind farm is creating some kind of noise that is associated with residents feeling an “unacceptable presence of sensation inside a dwelling”.

It's also worth noting that contrary to a belief by some parliamentarians that wind farms are flouting noise restrictions, Cooper also found the wind farm was completely in compliance with the relevant regulations. And the report also noted that, “there is not enough data from this study to justify any change in regulation”.