Editor’s Note: Henry Stephenson, a member of the Tisbury planning board, this week prepared a series of simulated images illustrating how proposed wind farms might affect views from the Gay Head Cliffs. The above image, a panorama taken from the Gay Head overlook, shows what turbines placed in planned state and federal areas would look like if the current version of the oceans plan is carried out. What follows is Mr. Stephenson’s written explanation of this and other images.

turbines
Image shows projected visual impact of turbines in both state and federal waters.

The panoramas are composites of individual photos taken in October 2009. The photos are taken from the Gay Head overlook, about 100 feet above the water.

The images of the turbines themselves are taken from the flyer advertising the state hearing on their oceans plan.

Care was taken to create an accurate impression of the scale and readability of the turbines in the water. A wide-angle lens will make images seem smaller and farther away than they really are, while a telephoto will make them seem larger and closer. Moreover, a wide-angle lens often includes a large amount of foreground and sky which also diminishes the actual impression that a viewer gets when looking out toward the horizon. Consequently, a panorama made up of a composite of standard sized photos seems to offer the most accurate impression of the actual view.

The height of Noman’s Land and Cuttyhunk is known from USGS data. Noman’s is 110 feet high and Cuttyhunk is 154 feet. Therefore a turbine adjacent to the islands can be proportioned accordingly, i.e. if a turbine is plus or minus 450 feet high, it will be about 4.1 times higher than the elevation of Noman’s. The heights of turbines that are in front of or to the rear of those can then be adjusted accordingly.

The width of the islands as seen from Gay Head is also known — they are each about 1.5 miles wide. Since the boundary of the state waters is three miles from the islands, the horizontal distribution of the turbines along that plane will be about double the width of the island.

Noman’s is 5.4 miles from Gay Head and Cuttyhunk is 6.8 miles and the state development area is confined largely to a three-mile semicircle around them.

The boundary of the federal development area on the other hand is actually closer. Between the two state development areas, there is an approximately 4.5-mile span of open water directly facing the Gay Head overlook. This area could be completely filled in by turbines built within the federal development area which starts just three miles offshore. Approximately 100 turbines are shown within the Noman’s area to the south and about 70 are shown within the Cuttyhunk area to the north. Another 100 or so are indicated in the federal area. The federal area is much more extensive but the illustration shows the visual impact.