Den Brook Timeline:
|2005||–||RES submit planning application to West Devon Borough Council (WDBC) for nine wind turbines in the Den Brook valley between Bow, Spreyton and North Tawton|
|2006 Jan||–||WDBC refuses planning permission|
|2006 May||–||RES file Planning Appeal|
|2007 Feb||–||Planning Inspector grants planning permission|
|2007 Mar||–||Mike Hulme lodges Judicial Appeal|
|2008 Mar||–||Judicial Appeal refused by High Court|
|2008 Apr||–||Hulme appeals to Court of Appeal|
|2008 Aug||–||Court of Appeal requires redetermination of Planning Appeal by Inspector|
|2009 Dec||–||Inspector grants planning permission with conditions |
|2010 Jan||–||Hulme lodges appeal to Court of Appeal|
|2011 May||–||Court of Appeal upholds planning permission and conditions |
|2013 Apr||–||RES applies to amend AM conditions (see 2012 RES presentation on AM, tonality and impulses )|
|2013 Aug||–||RES withdraws application to amend AM conditions|
|2014 Feb||–||RES submits scheme for complying with AM conditions |
|2015 Aug||–||RES begins construction|
The “Den Brook Amplitude Modulation Condition”:
Excess amplitude modulation was defined in condition 20 of the December 2009 planning permission as any change, upon complaint, outside the dwelling, in LAeq,125ms of >3 dB in any 2-second period ≥5 times in any minute with LAeq,1min ≥28 dB and such excess occurring in ≥6 minutes in any hour.
“LAeq,125ms” is the equivalent A-weighted continuous sound level (average) over a 125-millisecond period, “LAeq,1min” over a 1-minute period.
In other words, a 125-ms pulse of 3 dBA or greater (3 dB being the difference in noise level detectable by the human ear) can not occur in any 2-second period five or more times in six or more minutes of any hour, when those minute-long average noise levels are 28 dBA or more.