Wind Conditions

IMPORTANT NEWS: The public comment period for Rocky Forge has ended. Apex must now produce a document containing all of the comments and their responses. When that document becomes available, we will post it on our site. Click here  to view the application documents provided by Apex to the DEQ.

We are concerned about the viability of this project because it is being proposed in a part of Virginia where winds are marginal, at best, for creating power. While we all experience windy days in the Shenandoah Valley, winds necessary to sustain reliable electric generation do not exist. When US energy consumption is at its peak, typically during early evenings in mid-summer, wind is practically nonexistent here. Winds are mostly still unless a thunderstorm develops.

In their proposal, Apex reported they plan to use a Nordex 131/3000 turbine. The data sheet on this turbine reports that the turbine cut-in speed is 3 meters per second (m/s) (6.7 mph), optimum speed is 11.1 m/s (24.8 mph), and cutoff speed is 20 m/s (44.7 mph). Apex’s wind study map show the wind speeds vary from 5 m/s to 7.5 m/s on the portion of North Mountain where they plan to construct the wind project. The Apex wind study does not report percent calm winds, winds below the cut-in speed.

More specifically:

Number of Turbines Reported Mean Wind Speed (m/s) Reported Wind Speed (mph)
10 7 to 7.5 15.6 to 16.7
2 6.5 to 7 14.5 to 15.6
6 6 to 6.5 13.4 to 14.5
4 5.5 to 6 12.3 to 13.4
3 5 to 5.5 11.2 to 12.3

This information suggests that, for all the turbines, the mean wind speed is below the optimum speed needed to produce the rated 3 MW per turbine. Three of the turbines are located in areas where their study shows a mean speed of 5 to 5.5 m/s, so much of the time the turbines will be in winds below the cut-in speed.

We reviewed a feasibility study by PMJ Interconnect, LLC, owner of the transmission infrastructure in the area. They propose to construct a connection to the project that will carry 10.1 MW. PMJ’s study suggests that based on either Apex’s wind data or their own study, they do not expect the Project to produce more than 10.1 MW, which is equivalent to 12.9% of the rated output of the facility. This confirms the notion that the wind facility is planned in an area where winds are marginal, and little and intermittent power will be generated. Thus, the claim by Apex on the Rocky Forge website that the installation “which is expected to generate enough energy to power up to 20,000 homes annually” is a gross exaggeration.

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