Height of the Turbines in the now-withdrawn proposed Helensburgh wind farm
At 86.5 metres to blade tip, the application’s turbine height was much too big.
The A&B Council’s Landscape Wind Energy Capacity Study (LWECS of 2012) said the location is unsuited to such big turbines.
A&B Council’s letter to the developers dated 22nd August 2013 drew specific attention to the LWECS restriction mentioned above, pointing out that it is a planning material consideration.
This would have been a departure from Council-adopted policy which is a material consideration and it was pursued after ample warning.
Argyll and Bute Council : Argyll and Bute Landscape Wind Energy Capacity Study (2012)
This LWECS study was commissioned by A&BC and it covers the whole of Argyll and Bute. Only the conclusions regarding the site proposed for the Helensburgh turbines are discussed here. This is designated as “Open Ridgeland”.
The most relevant conclusion is that turbines of this size are too big for the proposed site. In the words of the LWECS :
“There is no scope for the lager typologies to be located within this landscape type without incurring significant impacts on a number of sensitivity criteria.”
Sensitivity ratings are given for different criteria. These are :
“Scale and openness”
“Land cover pattern”
[“Perceptual qualities” (i.e. remoteness)]
[Landscape values” (i.e. whether the landscape has national designations)]
Of these, two are irrelevant to the proposed wind farm site : remoteness (because, clearly, it is not remote) and national designations, though the report notes that it is directly beside the National Park and close to a National Scenic Area. These two are therefore excluded in the following summary which is our interpretation of the report.
For turbines over 80 metres, the sensitivity is rated as “High” or “High-medium” for five of the six criteria. That means the turbines are entirely unsuitable.
For turbines 50-80 metres. The sensitivity is rated as “High-med” for landscape context and for visual amenity. It is medium, for Built environment. Three of the other criteria are recorded as “Medium” or “Medium-low”. That means still substantially inappropriate. In these terms the site is unsuitable for turbines in this category. The height of 74 metres mentioned by the developers at one stage would not be suitable by the landscape criterion.
For turbines 35-50 metres. Four of the six criteria are designated as either “Medium” or “”Highmedium" sensitivity. This report has wrongly been referred to as supporting turbines of 50 metres. That seems not to be accurate. Indeed, for the “Visual amenity” criterion it is assessed as “Highmed”, meaning substantially unacceptable, with the observation “This landscape is highly visible from many areas around the well-settled Firth of Clyde” and goes on to report visibility from the Rosneath Peninsula, Cardross, Greenock and other locations and mentions proximity to the National Park. It is clear that 50 metres is not acceptable on that location in landscape (and other) terms.
For turbines 20-35 metres. Here the landscape context sensitivity rating is “Medium-low”, while the “Visual amenity” sensitivity rating is “Medium”. Thus, even for turbines as small as 20 metres there are reservations about that site, though “There is greater scope for this smaller typology to be sited on lower hill slopes avoiding intrusion on key views and to be visually associated with existing buildings so limiting clutter.” The wind farm is not proposed for lower slopes.
Thus the case for turbines of ANY height is questionable and clearly inappropriate for any above 35 metres.
This report has been adopted by Argyll and Bute Council and is accepted by Scottish Natural Heritage. In its scoping opinion dated 22.8.13 addressed to the developers, A&BC were blunt. They stated “The proposal is not supported by the development recommendations cited in the LWECS. SNH support the capacity study and recommend that the findings are used to inform the strategic pattern of wind energy development in Argyll and Bute.”
Height-to-power ratio The higher the turbine, the more power. The developers have mentioned different heights at different times – between 80 and 120 initially; 74 at one point; and 86.5 in the end.
The developers have made no mention of vertical axis turbines which are only 10 meres high but which operate at lower wind speeds than conventional (horizontal axis) turbines and are easier to maintain. However, they generate less power per turbine.
CONCLUSION The proposed turbines would be very conspicuous, could dominate the landscape, would alter the character of Helensburgh and would be very greatly in excess of what the Council’s Landscape Wind Energy Capacity Study sees as allowable. Even the lower (74 m) structures mentioned at one stage by the developers would have seriously exceeded the guidelines.