Stantec has just released the second draft environmental report, dated November 2011. It follows the first draft report which was dated May 2011, and about which I’ve already posted. There are two significant differences. Most importantly Algonquin has replaced the Vestas 1.8MW turbines with Siemans SWT-2.3-113 turbines. These are monsters. They sweep a full 10,000 sq meters, compared to 7850 for the Vestas. The blades are 113 meters in diameter, compared to 100. From the ground to the tip is about 156 m, or 512 feet. The second change is some waffling on the temporary dock – it is now either a temporary or permanent dock, to be decided. Still Stantec is confident they won’t trigger a federal environmental screening.
For the neighbors this change of turbines is probably bad news. Although Stantec hasn’t released as much information about the Siemans as they did about the Vestas, my calculations show that they are slightly less efficient at pulling energy from the wind, but have a wider wind speed operating range. Of more concern is that the larger and higher blades will create more turbulence and be more affected by wind shear – thus producing more noise. A recent study showed that turbines closer than 15 diameters lost efficiency due to turbulence, and on narrow Amherst Island there’s little doubt the turbines will be closer than that.